Manufacturing method of light-emitting device, light-emitting device, module, and electronic device

ABSTRACT

A highly reliable light-emitting device is provided. A yield in a manufacturing process of a light-emitting device is increased. A light-emitting device is provided in which a non-light-emitting portion having a frame-like shape outside a light-emitting portion includes a portion thinner than the light-emitting portion. A light-emitting element and a bonding layer are formed over a substrate. The light-emitting element is sealed by overlapping a pair of substrates and curing the bonding layer. Then, while the cured bonding layer is heated, pressure is applied to at least a portion of the non-light-emitting portion with a member having a projection.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No.15/897,191, filed Feb. 15, 2018, now allowed, which is a divisional ofU.S. application Ser. No. 15/220,455, filed Jul. 27, 2016, now U.S. Pat.No. 9,917,282, which claims the benefit of foreign priority applicationsfiled in Japan as Serial No. 2015-150777 on Jul. 30, 2015, and SerialNo. 2016-119834 on Jun. 16, 2016, all of which are incorporated byreference.

TECHNICAL FIELD

One embodiment of the present invention relates to a light-emittingdevice, a module, an electronic device, and a manufacturing methodthereof. In particular, one embodiment of the present invention relatesto a light-emitting device utilizing organic electroluminescence (EL),and a manufacturing method thereof.

Note that one embodiment of the present invention is not limited to theabove technical field. Examples of the technical field of one embodimentof the present invention include a semiconductor device, a displaydevice, a light-emitting device, a power storage device, a memorydevice, an electronic device, a lighting device, an input device (suchas a touch sensor), an input/output device (such as a touch panel), amethod for driving any of them, and a method for manufacturing any ofthem.

BACKGROUND ART

Recent light-emitting devices are expected to be applied to a variety ofuses and become diversified.

For example, light-emitting devices for mobile devices and the like arerequired to be thin, lightweight, and less likely to be broken.

Light-emitting elements utilizing EL (also referred to as EL elements)have features such as ease of thinning and lightening, high-speedresponse to input signal, and driving with a direct-current low voltagesource; therefore, application of the light-emitting elements tolight-emitting devices has been proposed.

For example, Patent Document 1 discloses a flexible active matrixlight-emitting device in which an organic EL element and a transistorserving as a switching element are provided over a film substrate.

An organic EL element has a problem in that entry of impurities such asmoisture or oxygen from the outside erodes the reliability.

When impurities such as moisture or oxygen enter an organic compound ora metal material contained in an organic EL element from the outside ofthe organic EL element, the lifetime of the organic EL element issignificantly shortened in some cases. This is because the organiccompound or the metal material contained in the organic EL elementreacts with the impurities and thus deteriorates.

Thus, a technique to seal an organic EL element for preventing entry ofimpurities has been researched and developed.

Patent Document

-   [Patent Document 1] Japanese Published Patent Application No.    2014-197522

DISCLOSURE OF INVENTION

An object of one embodiment of the present invention is to improve thereliability of a light-emitting device. An object of one embodiment ofthe present invention is to increase a yield in a manufacturing processof a light-emitting device.

An object of one embodiment of the present invention is to provide alight-emitting device with a curved surface. An object of one embodimentof the present invention is to provide a flexible light-emitting device.An object of one embodiment of the present invention is to provide alightweight light-emitting device. An object of one embodiment of thepresent invention is to provide a thin light-emitting device. An objectof one embodiment of the present invention is to provide a novellight-emitting device or the like.

Note that the descriptions of these objects do not disturb the existenceof other objects. In one embodiment of the present invention, there isno need to achieve all the objects. Other objects can be derived fromthe description of the specification, the drawings, and the claims.

One embodiment of the present invention is a method for manufacturing alight-emitting device which includes a light-emitting portion includinga light-emitting element and a non-light-emitting portion having aframe-like shape outside the light-emitting portion. Thenon-light-emitting portion preferably includes a spacer and an inorganicinsulating layer.

A method a for manufacturing a light-emitting device in one embodimentof the present invention includes a first step of forming alight-emitting element over a first substrate, a second step of forminga bonding layer over the first substrate or a second substrate, a thirdstep of overlapping the first substrate and the second substrate so asto position the light-emitting element in a space surrounded by thebonding layer, the first substrate, and the second substrate, a fourthstep of curing the bonding layer, and a fifth step of applying pressureto at least a portion of a non-light-emitting portion with a memberhaving a projection while heating the bonding layer after curing thebonding layer.

In the manufacturing method a, it is preferable to form a spacer and aninorganic insulating layer covering a side surface and a top surface ofthe spacer over the first substrate or the second substrate before thesecond step. In the fifth step of the manufacturing method a, theprojection preferably overlaps with the inorganic insulating layer.

A method b for manufacturing a light-emitting device in one embodimentof the present invention includes a first step of forming a separationlayer over a first substrate, a second step of forming a layer to beseparated over the separation layer, a third step of forming a bondinglayer over the first substrate or a second substrate, a fourth step ofoverlapping the first substrate and the second substrate, a fifth stepof curing the bonding layer, a sixth step of separating the firstsubstrate and the layer to be separated from each other, and a seventhstep of applying pressure to at least a portion of a non-light-emittingportion with a member having a projection while heating the bondinglayer after curing the bonding layer. In the second step of themanufacturing method b, an insulating layer over the separation layerand a light-emitting element over the insulating layer are formed as thelayer to be separated. In the third step of the manufacturing method b,the bonding layer is formed to overlap with the separation layer and thelayer to be separated. In the fourth step of the manufacturing method b,the light-emitting element is positioned in a space surrounded by thebonding layer, the first substrate, and the second substrate.

The manufacturing method b may include a step of attaching a thirdsubstrate to the separated layer between the sixth step and the seventhstep. Alternatively, the manufacturing method b may include the step ofattaching the third substrate to the separated layer after the seventhstep.

In the manufacturing method b, it is preferable to form a spacer and aninorganic insulating layer covering a side surface and a top surface ofthe spacer over the first substrate or the second substrate before thethird step. In the seventh step of the manufacturing method b, theprojection preferably overlaps with the inorganic insulating layer.

A method c for manufacturing a light-emitting device in one embodimentof the present invention includes a first step of forming a firstseparation layer over a first substrate, a second step of forming afirst layer to be separated over the first separation layer, a thirdstep of forming a second separation layer over a second substrate, afourth step of forming a second layer to be separated over the secondseparation layer, a fifth step of forming a bonding layer over the firstsubstrate or the second substrate, a sixth step of overlapping the firstsubstrate and the second substrate, a seventh step of curing the bondinglayer, an eighth step of separating the first substrate and the firstlayer to be separated from each other, a ninth step of attaching a thirdsubstrate to the first separated layer, a tenth step of separating thesecond substrate and the second layer to be separated from each other,and an eleventh step of applying pressure to at least a portion of anon-light-emitting portion with a member having a projection whileheating the bonding layer after curing the bonding layer. In themanufacturing method c, an insulating layer and a light-emitting elementover the insulating layer are formed as the first layer to be separatedor the second layer to be separated. In the fifth step of themanufacturing method c, the bonding layer is formed to overlap with thefirst separation layer and the first layer to be separated. In the sixthstep of the manufacturing method c, the light-emitting element ispositioned in a space surrounded by the bonding layer, the firstsubstrate, and the second substrate.

The manufacturing method c may include a step of attaching a fourthsubstrate to the second separated layer between the tenth step and theeleventh step. Alternatively, the manufacturing method c may include thestep of attaching the fourth substrate to the second separated layerafter the eleventh step.

The manufacturing method c preferably includes the step of forming apartition over the first substrate or the second substrate before thesixth step. The partition is formed to surround the bonding layer.

In the manufacturing method c, it is preferable to form a spacer and aninorganic insulating layer covering a side surface and a top surface ofthe spacer over the first substrate or the second substrate before thefifth step. In the eleventh step of the manufacturing method c, theprojection preferably overlaps with the inorganic insulating layer.

A light-emitting device in one embodiment of the present inventionincludes a light-emitting portion and a non-light-emitting portionhaving a frame-like shape outside the light-emitting portion. Thelight-emitting device includes a first flexible substrate, a secondflexible substrate, a first bonding layer, a second bonding layer, afirst insulating layer, and a first functional layer. The first bondinglayer is positioned between the first flexible substrate and the firstinsulating layer. The second bonding layer is positioned between thesecond flexible substrate and the first insulating layer. The firstfunctional layer is positioned between the second bonding layer and thefirst insulating layer. The first bonding layer and the second bondinglayer partly overlap with each other with the first insulating layerprovided therebetween. The light-emitting portion includes alight-emitting element in the first functional layer. Thenon-light-emitting portion includes a spacer and an inorganic insulatinglayer in the first functional layer. The inorganic insulating layercovers a side surface and a top surface of the spacer. A gap between thefirst flexible substrate and the second flexible substrate is smaller ina first portion of the non-light-emitting portion than in thelight-emitting portion. The first portion preferably includes theinorganic insulating layer.

One embodiment of the present invention is a module including any of thelight-emitting devices in the above embodiments. The module is providedwith a connector such as a flexible printed circuit (hereinafter alsoreferred to as an FPC) or a tape carrier package (TCP) or is mountedwith an integrated circuit (IC) by a chip on glass (COG) method, a chipon film (COF) method, or the like.

Any of the above embodiments of the present invention may be applied toa display device or an input/output device (such as a touch panel)instead of the light-emitting device.

One embodiment of the present invention is an electronic deviceincluding the above-mentioned module and at least one of an antenna, abattery, a housing, a camera, a speaker, a microphone, and an operationbutton.

One embodiment of the present invention can improve the reliability of alight-emitting device. One embodiment of the present invention canincrease a yield in a manufacturing process of a light-emitting device.

One embodiment of the present invention can provide a light-emittingdevice with a curved surface. One embodiment of the present inventioncan provide a flexible light-emitting device. One embodiment of thepresent invention can provide a lightweight light-emitting device. Oneembodiment of the present invention can provide a thin light-emittingdevice. One embodiment of the present invention can provide a novellight-emitting device or the like.

Note that the descriptions of these effects do not disturb the existenceof other effects. One embodiment of the present invention does notnecessarily achieve all the effects. Other effects can be derived fromthe description of the specification, the drawings, and the claims.

BRIEF DESCRIPTION OF DRAWINGS

FIGS. 1A to 1E are a flowchart and cross-sectional views illustrating anexample of a method for manufacturing a light-emitting device.

FIGS. 2A to 2G are cross-sectional views illustrating an example of amethod for manufacturing a light-emitting device.

FIGS. 3A to 3G are a flowchart, cross-sectional views, and top viewsillustrating an example of a method for manufacturing a light-emittingdevice.

FIGS. 4A to 4D are a flowchart and cross-sectional views illustrating anexample of a method for manufacturing a light-emitting device.

FIGS. 5A to 5F are a flowchart and cross-sectional views illustrating anexample of a method for manufacturing a light-emitting device.

FIGS. 6A to 6D are cross-sectional views illustrating an example of amethod for manufacturing a light-emitting device.

FIG. 7 is a flowchart illustrating an example of a method formanufacturing a light-emitting device.

FIGS. 8A to 8E are cross-sectional views illustrating an example of amethod for manufacturing a light-emitting device.

FIGS. 9A to 9E are cross-sectional views illustrating an example of amethod for manufacturing a light-emitting device.

FIGS. 10A and 10B are a flowchart and a cross-sectional viewillustrating an example of a method for manufacturing a light-emittingdevice.

FIGS. 11A to 11D are cross-sectional views illustrating an example of amethod for manufacturing a light-emitting device.

FIGS. 12A to 12H are top views each illustrating an example of alight-emitting device.

FIGS. 13A and 13B are cross-sectional views each illustrating an exampleof a method for manufacturing a light-emitting device.

FIGS. 14A to 14G are top views of members having projections and across-sectional view illustrating the projection of the member and adepression in a light-emitting device.

FIGS. 15A and 15B are a top view of a member having a projection and across-sectional view illustrating a method for manufacturing alight-emitting device.

FIGS. 16A and 16B are a top view and a cross-sectional view illustratingan example of a light-emitting device.

FIGS. 17A to 17D are a cross-sectional view illustrating an example of alight-emitting device and a top view and cross-sectional viewsillustrating an example of a transistor.

FIGS. 18A and 18B are a top view and a cross-sectional view illustratingan example of a light-emitting device.

FIGS. 19A and 19B are cross-sectional views illustrating an example of alight-emitting device.

FIGS. 20A and 20B are cross-sectional views each illustrating an exampleof a light-emitting device.

FIGS. 21A and 21B are cross-sectional views each illustrating an exampleof a light-emitting device.

FIGS. 22A and 22B are cross-sectional views each illustrating an exampleof a light-emitting device.

FIGS. 23A to 23C are cross-sectional views each illustrating an exampleof a light-emitting device.

FIGS. 24A to 24C are a top view and cross-sectional views illustratingan example of an input/output device.

FIGS. 25A and 25B are perspective views illustrating an example of aninput/output device.

FIGS. 26A and 26B are cross-sectional views each illustrating an exampleof an input/output device.

FIGS. 27A to 27C are cross-sectional views illustrating examples of aninput/output device.

FIGS. 28A, 28B, 28C1, 28C2, 28D, 28E, 28F, 28G, and 28H illustrateexamples of electronic devices and lighting devices.

FIGS. 29A1, 29A2, 29B, 29C, 29D, 29E, 29F, 29G, 29H, and 291 illustrateexamples of electronic devices.

FIGS. 30A to 30E illustrate examples of electronic devices.

FIG. 31 shows measured XRD spectra of samples.

FIGS. 32A and 32B are TEM images of samples and FIGS. 32C to 32L areelectron diffraction patterns thereof.

FIGS. 33A to 33C show EDX mapping images of a sample.

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiments will be described in detail with reference to the drawings.Note that the present invention is not limited to the followingdescription, and it will be easily understood by those skilled in theart that various changes and modifications can be made without departingfrom the spirit and scope of the present invention. Therefore, thepresent invention should not be construed as being limited to thedescription in the following embodiments.

Note that in the structures of the invention described below, the sameportions or portions having similar functions are denoted by the samereference numerals in different drawings, and description of suchportions is not repeated. Furthermore, the same hatch pattern is appliedto similar functions, and these are not especially denoted by referencenumerals in some cases.

In addition, the position, size, range, or the like of each structureillustrated in drawings is not accurately represented in some cases foreasy understanding. Therefore, the disclosed invention is notnecessarily limited to the position, size, range, or the like disclosedin the drawings.

Note that the terms “film” and “layer” can be interchanged with eachother depending on the case or circumstances. For example, the term“conductive layer” can be changed into the term “conductive film.” Also,the term “insulating film” can be changed into the term “insulatinglayer.”

Embodiment 1

In this embodiment, a light-emitting device of one embodiment of thepresent invention and a manufacturing method thereof will be describedwith reference to FIGS. 1A to 1E, FIGS. 2A to 2G, FIGS. 3A to 3G, FIGS.4A to 4D, FIGS. 5A to 5F, FIGS. 6A to 6D, FIG. 7, FIGS. 8A to 8E, FIGS.9A to 9E, FIGS. 10A and 10B, FIGS. 11A to 11D, FIGS. 12A to 12H, FIGS.13A and 13B, FIGS. 14A to 14G, and FIGS. 15A and 15B.

Alight-emitting device including an EL element is mainly described inthis embodiment as an example; however, one embodiment of the presentinvention is not limited to this example. A light-emitting device or adisplay device including another light-emitting element or displayelement is also one embodiment of the present invention. Moreover, oneembodiment of the present invention is not limited to the light-emittingdevice or the display device and can be applied to a variety of devicessuch as a semiconductor device and an input/output device.

The light-emitting device of one embodiment of the present inventionincludes a light-emitting portion and a non-light-emitting portion. Thelight-emitting portion includes a light-emitting element. Thenon-light-emitting portion is provided outside the light-emittingportion so as to have a frame-like shape.

In some cases, a functional element (e.g., a light-emitting element or atransistor) included in a light-emitting device deteriorates because ofentry of impurities such as moisture from the outside, which mightreduce the reliability. Entry of impurities in the thickness directionof the light-emitting device (i.e., entry through a light-emittingsurface and a surface facing the light-emitting surface) can beminimized by providing the functional element between a pair of layers(substrates, insulating layers, or the like) with an excellent gasbarrier property. At a side surface of the light-emitting device, abonding layer for sealing the light-emitting element or the like isexposed to the air. When a resin is used for the bonding layer, forexample, it is possible to achieve higher impact resistance, higher heatresistance, and greater robustness against deformation due to externalforce or the like than when a glass frit or the like is used. The use ofa resin for the bonding layer can increase the flexibility and theresistance to bending of the light-emitting device. On the other hand, aresin has an insufficient gas barrier property, water-resistantproperty, or moisture-resistant property in some cases.

In view of the above, in one embodiment of the present invention, thenon-light-emitting portion of the light-emitting device has a portionwhose thickness is smaller than that of the light-emitting portion.

When the light-emitting device (or the bonding layer) has a regionhaving a smaller thickness than other portions, impurities such asmoisture entering through a side surface of the light-emitting device donot easily pass through the region. As a result, the impurities are lesslikely to reach the functional element than when the light-emittingdevice (or the bonding layer) has a uniform thickness, and a reductionin reliability of the light-emitting device can be inhibited.

In one embodiment of the present invention, the reliability of thelight-emitting device can be improved by changing its shape (or thethickness of the bonding layer), which allows the material used for thebonding layer to be selected from a wider range of options. For example,a light-emitting device having a long lifetime can be manufactured evenwhen a resin is used for the bonding layer.

Note that the thinner region may be locally provided in thenon-light-emitting portion. Alternatively, the thickness may decrease ina continuous (smooth) manner from the light-emitting portion side of thenon-light-emitting portion to an end portion of the light-emittingdevice.

Examples of the manufacturing method of the light-emitting device of oneembodiment of the present invention are described below.

<Manufacturing Method 1>

FIG. 1A illustrates a flowchart of a manufacturing method 1 of thelight-emitting device.

[S1-1: Form a Light-Emitting Element]

First, a pair of substrates (a substrate 11 and a substrate 19) areprepared. Next, a light-emitting element 15 is formed over the substrate11 (FIG. 1B). In FIG. 1B and the like, a portion where thelight-emitting element 15 is provided over the substrate 11 isillustrated as a light-emitting portion 25, and a portion other than thelight-emitting portion 25 is illustrated as a non-light-emitting portion26.

As the pair of substrates, substrates having at least heat resistancehigh enough to withstand process temperature in a manufacturing processare used. A material such as glass, quartz, sapphire, ceramic, anorganic resin, a metal, an alloy, or a semiconductor can be used for thepair of substrates. The substrate on the side from which light from thelight-emitting element is extracted is formed using a material whichtransmits the light.

A substrate having flexibility (hereinafter referred to as a flexiblesubstrate) is preferably used as each of the pair of substrates. Forexample, an organic resin; or glass, a metal, or an alloy that is thinenough to have flexibility can be used. For example, the thickness ofthe flexible substrate is preferably greater than or equal to 1 μm andless than or equal to 200 μm, further preferably greater than or equalto 1 μm and less than or equal to 100 μm, still further preferablygreater than or equal to 10 μm and less than or equal to 50 μm, yetfurther preferably greater than or equal to 10 μm and less than or equalto 25 μm. The thickness and hardness of the flexible substrate are setin the range where mechanical strength and flexibility can be balancedagainst each other. The flexible substrate may have a single-layerstructure or a stacked-layer structure.

Examples of materials for metal substrates include aluminum, copper,nickel, and the like. Examples of materials for alloy substrates includean aluminum alloy, stainless steel, and the like. Examples of materialsfor semiconductor substrates include silicon and the like.

Examples of materials having flexibility and a light-transmittingproperty include polyester resins such as polyethylene terephthalate(PET) and polyethylene naphthalate (PEN), a polyacrylonitrile resin, anacrylic resin, a polyimide resin, a polymethyl methacrylate resin, apolycarbonate (PC) resin, a polyethersulfone (PES) resin, polyamideresins (such as nylon and aramid), a polysiloxane resin, a cycloolefinresin, a polystyrene resin, a polyamide-imide resin, a polyurethaneresin, a polyvinyl chloride resin, a polyvinylidene chloride resin, apolypropylene resin, a polytetrafluoroethylene (PTFE) resin, and an ABSresin. In particular, a material having a low coefficient of linearexpansion is preferable, and for example, a polyamide-imide resin, apolyimide resin, a polyamide resin, or PET can be suitably used. Asubstrate in which a fibrous body is impregnated with a resin (alsoreferred to as prepreg) or a substrate whose coefficient of linearexpansion is reduced by mixing an inorganic filler with an organic resincan also be used.

As the light-emitting element 15, a self-luminous element can be used,and an element whose luminance is controlled by current or voltage isincluded in the category of the light-emitting element. For example, alight-emitting diode (LED), an organic EL element, an inorganic ELelement, or the like can be used. Note that one embodiment of thepresent invention is not limited to the light-emitting device and can beapplied to display devices including various display elements. Forexample, instead of the light-emitting element, a liquid crystalelement, an electrophoretic element, a display element using microelectro mechanical systems (MEMS), or the like can be used in a displaydevice.

In addition to the light-emitting element 15, one or more of variousfunctional elements such as a transistor, a resistor, a switchingelement, and a capacitor can be formed over the substrate 11.

A region where a functional element is provided is not limited to thelight-emitting portion 25. For example, one or more of a signal linedriver circuit, a scan line driver circuit, an external connectionelectrode, and the like can be formed in the non-light-emitting portion26. The external connection electrode is electrically connected to anexternal input terminal through which a signal (e.g., a video signal, aclock signal, a start signal, or a reset signal) or a potential from theoutside is transmitted.

[S1-2: Form a Bonding Layer]

Next, a bonding layer 17 is formed over the substrate 11 or thesubstrate 19.

The thickness of the bonding layer 17 can be greater than or equal to 1μm and less than or equal to 200 μm, preferably greater than or equal to1 μm and less than or equal to 100 μm, further preferably greater thanor equal to 1 μm and less than or equal to 50 μm, for example.

There is no particular limitation on methods for forming the bondinglayer 17; for example, a droplet discharge method, a printing method (ascreen printing method or an offset printing method), a coating methodsuch as a spin coating method or a spray coating method, a dippingmethod, a dispenser method, or a nanoimprint method can be employed.

As the glass transition temperature of an adhesive used for the bondinglayer 17 decreases, the bonding layer 17 becomes more easily depressedwhen pressure is applied to the bonding layer 17 in a later step.Therefore, a portion where the bonding layer 17 is extremely thin can beeasily formed in the light-emitting device, and the reliability of thelight-emitting device can be improved. On the other hand, as the glasstransition temperature of the adhesive used for the bonding layer 17increases, the heat resistance of the light-emitting device increases.Therefore, the glass transition temperature of the adhesive used for thebonding layer 17 is preferably higher than or equal to 60° C. and lowerthan or equal to 120° C., further preferably higher than or equal to 80°C. and lower than or equal to 100° C.

The bonding layer 17 preferably has thermoplasticity as described later.

A thermosetting adhesive or a UV delay curing adhesive is preferablyused for the bonding layer 17. Any of various curable adhesives, e.g., aphotocurable adhesive such as an ultraviolet curable adhesive, areactive curable adhesive, and an anaerobic adhesive can also be used.Examples of resins included in the adhesives include an epoxy resin, anacrylic resin, a silicone resin, a phenol resin, a polyimide resin, animide resin, a polyvinyl chloride (PVC) resin, a polyvinyl butyral (PVB)resin, and an ethylene vinyl acetate (EVA) resin. In particular, amaterial with low moisture permeability, such as an epoxy resin, ispreferred.

Furthermore, the resin may include a drying agent. As the drying agent,for example, a substance that adsorbs moisture by chemical adsorption,such as an oxide of an alkaline earth metal (e.g., calcium oxide orbarium oxide), can be used. Alternatively, a substance that adsorbsmoisture by physical adsorption, such as zeolite or silica gel, may beused. The drying agent is preferably included, in which case it cansuppress deterioration of the functional element due to entry ofmoisture in the air and can improve the reliability of thelight-emitting device.

The above resin may include a leveling agent or a surface-active agent.

When a leveling agent or a surface-active agent is added to the resin,surface tension of the resin can be reduced and the wettability thereofcan be increased. High wettability allows uniform application of theresin. Accordingly, inclusion of bubbles at the time of attachment ofthe pair of substrates can be inhibited, and the probability of acohesive failure of the bonding layer and interfacial failure betweenthe bonding layer and a layer to be bonded can be reduced. Displaydefects of the light-emitting device can also be inhibited.

As the leveling agent or the surface-active agent, a material that doesnot adversely affect the light-emitting element and the like is used.For example, an epoxy resin to which a fluorine-based leveling agent isadded at greater than or equal to 0.01 wt % and less than or equal to0.5 wt % may be used.

In addition, a filler with a high refractive index or a light-scatteringmember may be mixed into the resin, in which case the efficiency oflight extraction from the light-emitting element can be improved. Forexample, titanium oxide, barium oxide, zeolite, zirconium, or the likecan be used.

[S1-3: Overlap the Pair of Substrates]

Next, the substrate 11 and the substrate 19 are overlapped such that thelight-emitting element 15 is positioned in a space surrounded by thebonding layer 17, the substrate 11, and the substrate 19 (FIG. 1C). Interms of reliability of the light-emitting device, this step ispreferably performed in a reduced-pressure atmosphere.

[S1-4: Cure the Bonding Layer]

Next, the bonding layer 17 is cured.

[S1-5: Apply Pressure to the Non-Light-emitting Portion while Heatingthe Bonding Layer]

Next, while the bonding layer 17 is heated, pressure is applied to atleast a portion of the non-light-emitting portion 26 by using a member21 a having a projection (FIG. 1D).

The bonding layer 17 becomes thinner at the portion to which pressure isapplied than at the other portion (FIG. 1E). It can also be said thatthe gap between the substrate 11 and the substrate 19 becomes narrowerin a portion of the non-light-emitting portion 26 than in thelight-emitting portion 25.

Examples of conditions under which impurities entering through a sidesurface of the light-emitting device do not easily reach thelight-emitting element 15 include a small minimum thickness of thelight-emitting device, a small minimum gap between the substrate 11 andthe substrate 19, and a small minimum thickness of the bonding layer 17.In one embodiment of the present invention, a purpose of the step ofapplying pressure to the non-light-emitting portion is to decrease atleast one of these three minimum values.

Note that an uneven thickness of the light-emitting portion 25 mightresult in degradation of display quality. In one embodiment of thepresent invention, the bonding layer 17 is changed in shape after beingcured once. After being cured, the bonding layer 17 is more rigid orless fluid than before being cured. Therefore, the bonding layer 17 canbe locally changed in shape by using the member 21 a having theprojection. The shape-changing region of the bonding layer 17 in thenon-light-emitting portion 26 does not expand excessively beyond an areato which pressure is directly applied with the projection. Therefore,the thinned region of the bonding layer 17 can be kept within thenon-light-emitting portion, and the thickness of the light-emittingportion 25 does not easily become uneven. In one embodiment of thepresent invention, the reliability of the light-emitting device can beimproved, and a decrease in viewing angle characteristics and adegradation of display quality of the light-emitting device can besuppressed.

A resin having thermoplasticity (hereinafter referred to as athermoplastic resin) is preferably used for the bonding layer 17. Anepoxy resin or the like can be suitably used as the thermoplastic resin.

The use of the thermoplastic resin allows the cured bonding layer 17 tobe softened by heating. For example, the bonding layer 17 is cured atapproximately 60° C. in the step S1-4, and the bonding layer 17 issoftened at approximately 100° C. in the step S1-5. The softened bondinglayer 17 can be more easily changed in shape by pressure applicationthan the fully cured bonding layer 17. In addition, the softened bondinglayer 17 can be more locally changed in shape than the fully curedbonding layer 17.

For example, pressure can be applied to at least a portion of thenon-light-emitting portion 26 with the use of a mold having aprojection. Specifically, the mold is made to overlap with the substrate11 or the substrate 19 so that the projection overlaps with thenon-light-emitting portion 26. Then, pressure is applied to the stackedstructure of a light-emitting device 10 and the mold. The light-emittingdevice 10 in a portion that overlaps with the projection and thevicinity thereof are pressed by the projection, where the bonding layer17 has a smaller thickness than in other portions. Thus, thenon-light-emitting portion 26 of the light-emitting device 10 can have afirst portion whose thickness is smaller than that of the light-emittingportion 25. Note that the non-light-emitting portion 26 may include,outside the thin first portion, a second portion whose thickness islarger than that of the first portion. The relation between thethickness in the second portion and that in the light-emitting portion25 is not particularly limited; the second portion may have a larger orsmaller thickness than or may have the same thickness as thelight-emitting portion 25.

Pressure is preferably applied to the light-emitting device 10 with theuse of an apparatus capable of applying pressure, such as a hot press.Examples of the hot press are given later in this embodiment.

In the above manner, the light-emitting device in which part of thenon-light-emitting portion 26 has a smaller thickness than thelight-emitting portion 25 can be manufactured. With this structure,entry of impurities such as moisture and oxygen into the light-emittingdevice or arrival thereof at the light-emitting element can beinhibited.

Formation of the thin region in the non-light-emitting portion 26 can beverified by observation of interference fringes generated in thenon-light-emitting portion 26, for example. In the non-light-emittingportion 26, a region including interference fringes may be formed tohave a width of greater than or equal to 0.1 mm, greater than or equalto 0.5 mm, or greater than or equal to 1 mm, and less than or equal to10 mm, less than or equal to 5 mm, or less than or equal to 2 mm, forexample. When interference fringes are generated in the light-emittingportion 25, display quality deteriorates in some cases. It is thuspreferable that in the light-emitting portion 25, interference fringesnot be formed and the thickness of the light-emitting portion 25 beuniform (or substantially uniform).

Although FIG. 1D illustrates an example of applying pressure to thenon-light-emitting portion 26 from the substrate 19 side with the use ofthe member 21 a having the projection, one embodiment of the presentinvention is not limited to this example. It is preferable that themember 21 a having the projection be positioned on the side closer tothe substrate 11 or the substrate 19 which is more flexible or thinnerthan the other, in which case pressure can be more easily applied to thenon-light-emitting portion 26.

FIG. 2A illustrates an example of applying pressure to thenon-light-emitting portion from the substrate 11 side with the use of amember 21 b having a projection. Also in this case, the bonding layer 17becomes thinner at the portion to which pressure is applied of thenon-light-emitting portion than at the other portion (FIG. 2B).

FIG. 2C illustrates an example of applying pressure to thenon-light-emitting portion from both the substrate 11 side and thesubstrate 19 side with the use of the members 21 a and 21 b having theprojections. In this example, the width, height, and position of theprojection of each of the members 21 a and 21 b can be individuallydetermined. When the projections of the members 21 a and 21 b overlapwith each other with the light-emitting device provided therebetween, amuch thinner portion than the light-emitting portion can be formed inthe non-light-emitting portion (FIG. 2D). This is preferable becauseimpurities entering through a side surface of the light-emitting devicedo not easily reach the light-emitting element 15 and a decrease inreliability of the light-emitting device can be suppressed. Note thatthe positions of the projections of the members 21 a and 21 b may bemisaligned with each other.

One or more portions to which pressure is to be applied with the member21 a having the projection are provided between an end portion of thelight-emitting portion 25 and an end portion of the light-emittingdevice. FIG. 1D illustrates an example in which there is one portion towhich pressure is to be applied with the projection between a left endportion of the light-emitting portion 25 and a left end portion of thelight-emitting device and there is another portion to which pressure isto be applied between a right end portion of the light-emitting portion25 and a right end portion of the light-emitting device. FIG. 2Eillustrates an example in which there are two portions at each end. Inthe example in FIG. 2E, two depressions (referring to depressed portionsor hollows) are provided at each of the left and right ends of thelight-emitting device (FIG. 2F). After that, the width of thenon-light-emitting portion of the light-emitting device may be decreasedby partly removing one of the two depressions which is located outwardlyfrom the other as illustrated in FIG. 2G (a decrease in width of thebezel of the light-emitting device). In that case, it is preferable tocut the light-emitting device so that the thinnest portion of thelight-emitting device remains. The light-emitting device in FIG. 2G hasa portion where the thickness thereof continuously (smoothly) decreasesfrom the light-emitting portion side of the non-light-emitting portiontoward an end portion of the light-emitting device.

Since the light-emitting device in FIG. 2G has the thin end portion,external impurities do not easily enter from the end portion. Thelight-emitting device in FIG. 2G also has the depression in thenon-light-emitting portion. Therefore, even when impurities enter fromthe end portion of the light-emitting device, the impurities do noteasily reach the light-emitting element.

Although the light-emitting element 15 is formed directly over thesubstrate 11 in the manufacturing method 1, one embodiment of thepresent invention is not limited to this example. A light-emittingelement or the like formed over a formation substrate 31 may betransferred to the substrate 11, as described in the followingmanufacturing methods 2 and 3. With this method, for example, a layer tobe separated which is formed over a formation substrate having high heatresistance can be transferred to a substrate having low heat resistance,and the formation temperature of the layer to be separated is notlimited by the substrate having low heat resistance. The layer to beseparated can be transferred to a substrate or the like that is morelightweight or flexible or thinner than the formation substrate, wherebya reduction in thickness and weight and improvement in flexibility ofthe light-emitting device can be achieved.

<Manufacturing Method 2>

FIG. 3A illustrates a flowchart of the manufacturing method 2 of thelight-emitting device.

[S2-1: Form a Separation Layer]

First, a pair of substrates (a formation substrate 31 and a substrate19) are prepared. Next, a separation layer 32 is formed over theformation substrate 31.

Although an example in which the separation layer is formed to have anisland shape is described here, one embodiment of the present inventionis not limited to such an example. In this step, materials are selectedthat would cause separation at the interface between the formationsubstrate 31 and the separation layer 32, the interface between theseparation layer 32 and an insulating layer 13 described later, or inthe separation layer 32 when the formation substrate 31 and theinsulating layer 13 are separated. In this embodiment, an example inwhich separation occurs at the interface between the insulating layer 13and the separation layer 32 is described; however, one embodiment of thepresent invention is not limited to such an example and depends on amaterial used for the separation layer 32 or the insulating layer 13.

As the formation substrate 31, a substrate having at least heatresistance high enough to withstand process temperature in amanufacturing process is used. A material such as glass, quartz,sapphire, ceramic, an organic resin, a metal, an alloy, or asemiconductor can be used for the formation substrate 31. The formationsubstrate 31 does not necessarily have a light-transmitting property.

Note that it is preferable to use a large-sized glass substrate as theformation substrate 31 in terms of productivity. For example, a glasssubstrate having a size greater than or equal to the 3rd generation (550mm×650 mm) and less than or equal to the 10th generation (2950 mm×3400mm) or a glass substrate having a larger size than the 10th generationcan be used.

In the case where a glass substrate is used as the formation substrate31, as a base film, an insulating layer such as a silicon oxide film, asilicon oxynitride film, a silicon nitride film, or a silicon nitrideoxide film is preferably formed between the formation substrate 31 andthe separation layer 32, in which case contamination from the glasssubstrate can be prevented.

The separation layer 32 can be formed using an element selected fromtungsten, molybdenum, titanium, tantalum, niobium, nickel, cobalt,zirconium, zinc, ruthenium, rhodium, palladium, osmium, iridium, andsilicon; an alloy material containing any of the elements; a compoundmaterial containing any of the elements; or the like. A crystalstructure of a layer containing silicon may be amorphous, microcrystal,or polycrystal. Furthermore, a metal oxide such as aluminum oxide,gallium oxide, zinc oxide, titanium dioxide, indium oxide, indium tinoxide, indium zinc oxide, or an In—Ga—Zn oxide can be used. Theseparation layer 32 is preferably formed using a high-melting-pointmetal material such as tungsten, titanium, or molybdenum, in which casethe degree of freedom of the process for forming the insulating layer 13and the functional element can be increased.

The separation layer 32 can be formed by, for example, a sputteringmethod, a plasma CVD method, a coating method (including a spin coatingmethod, a droplet discharging method, a dispensing method, and thelike), a printing method, or the like. The thickness of the separationlayer 32 is, for example, greater than or equal to 1 nm and less than orequal to 200 nm, preferably greater than or equal to 10 nm and less thanor equal to 100 nm.

In the case where the separation layer 32 has a single-layer structure,a tungsten layer, a molybdenum layer, or a layer containing a mixture oftungsten and molybdenum is preferably formed. Alternatively, a layercontaining an oxide or an oxynitride of tungsten, a layer containing anoxide or an oxynitride of molybdenum, or a layer containing an oxide oran oxynitride of a mixture of tungsten and molybdenum may be formed.Note that the mixture of tungsten and molybdenum is an alloy of tungstenand molybdenum, for example.

In the case where the separation layer 32 is formed to have astacked-layer structure including a layer containing tungsten and alayer containing an oxide of tungsten, the layer containing an oxide oftungsten may be formed as follows: the layer containing tungsten isformed first and an insulating layer containing an oxide is formedthereover, so that the layer containing an oxide of tungsten is formedat the interface between the tungsten layer and the insulating layer.Alternatively, the layer containing an oxide of tungsten may be formedby performing thermal oxidation treatment, oxygen plasma treatment,nitrous oxide (N₂O) plasma treatment, treatment with a highly oxidizingsolution such as ozone water, or the like on the surface of the layercontaining tungsten. Plasma treatment or heat treatment may be performedunder an atmosphere of oxygen, nitrogen, or nitrous oxide alone, or amixed gas of any of these gases and another gas. Surface condition ofthe separation layer 32 is changed by the plasma treatment or heattreatment, whereby adhesion between the separation layer 32 and theinsulating layer 13 can be controlled.

Note that the separation layer is not necessary in the case whereseparation at the interface between the formation substrate 31 and theinsulating layer 13 is possible. For example, a glass substrate is usedas the formation substrate 31, and an organic resin such as polyimide,polyester, polyolefin, polyamide, polycarbonate, or acrylic is formed incontact with the glass substrate. Next, adhesion between the formationsubstrate 31 and the organic resin is improved by laser lightirradiation or heat treatment. Then, the insulating layer 13, alight-emitting element 15, and the like are formed over the organicresin. After that, separation at the interface between the formationsubstrate 31 and the organic resin can be performed by performing laserlight irradiation with energy density higher than that of the abovelaser light irradiation or performing heat treatment at a temperaturehigher than that of the above heat treatment. Moreover, the interfacebetween the formation substrate 31 and the organic resin may be filledwith a liquid to perform separation.

In the case where the above method is employed, the insulating layer 13,the light-emitting element 15, a transistor, and the like are formedover the organic resin having low heat resistance, and thus it isdifficult to expose the substrate to high temperatures in themanufacturing process. Here, a manufacturing process at hightemperatures is dispensable for a transistor including an oxidesemiconductor; therefore, the transistor can be favorably formed overthe organic resin.

Note that the organic resin may be used as the substrate of the device.Alternatively, the organic resin may be removed and another substratemay be attached to the exposed surface using an adhesive.

Alternatively, separation at the interface between a metal layer and theorganic resin may be performed in the following manner: the metal layeris provided between the formation substrate 31 and the organic resin andcurrent is made to flow in the metal layer so that the metal layer isheated.

[S2-2: Form a Layer to be Separated]

Next, a layer to be separated is formed over the separation layer 32.FIG. 3B illustrates an example in which the insulating layer 13 over theseparation layer 32 and the light-emitting element 15 over theinsulating layer 13 are formed as the layer to be separated.

As the insulating layer 13, an insulating layer having an excellent gasbarrier property, an excellent water-resistant property, or an excellentmoisture-resistant property is preferably used.

As the insulating layer having an excellent moisture-resistant property,a film containing nitrogen and silicon (e.g., a silicon nitride film ora silicon nitride oxide film), a film containing nitrogen and aluminum(e.g., an aluminum nitride film), or the like can be used.

For example, the water vapor transmittance of the insulating layerhaving an excellent moisture-resistant property is lower than or equalto 1×10⁻⁵ [g/(m²·day)], preferably lower than or equal to 1×10⁻⁶[g/(m²·day)], further preferably lower than or equal to 1×10⁻⁷[g/(m²·day)], still further preferably lower than or equal to 1×10⁻⁸[g/(m²·day)].

Alternatively, a silicon oxide film, a silicon oxynitride film, analuminum oxide film, or the like can be used as the insulating layer 13.

The insulating layer 13 can be formed by a sputtering method, a plasmaCVD method, a coating method, a printing method, or the like. Forexample, the insulating layer 13 is formed at a temperature higher thanor equal to 250° C. and lower than or equal to 400° C. by a plasma CVDmethod, whereby the insulating layer 13 can be a dense film having anexcellent moisture-resistant property. Note that the thickness of theinsulating layer 13 is preferably greater than or equal to 10 nm andless than or equal to 3000 nm, further preferably greater than or equalto 200 nm and less than or equal to 1500 nm.

In addition to the light-emitting element 15, one or more of variousfunctional elements such as a transistor, a resistor, a switchingelement, and a capacitor can be formed as the layer to be separated overthe formation substrate 31. Alternatively, a display element other thanthe light-emitting element may be formed. A coloring layer or alight-blocking layer may be formed.

[S2-3: Form a Bonding Layer]

Next, a bonding layer 17 is formed over the formation substrate 31 orthe substrate 19.

The bonding layer 17 is preferably formed such that an end portion ofthe bonding layer 17 overlaps with the separation layer 32 and theinsulating layer 13. In that case, the yield of separation of theformation substrate 31 can be increased. In the case where the bondinglayer 17 is formed over the substrate 19, it is acceptable as long asthe end portion of the bonding layer 17 overlaps with the separationlayer 32 and the insulating layer 13 when the formation substrate 31 andthe substrate 19 are made to overlap with each other in the next stepS2-4.

[S2-4: Overlap the Pair of Substrates]

Next, the formation substrate 31 and the substrate 19 are overlappedsuch that the light-emitting element 15 is positioned in a spacesurrounded by the bonding layer 17, the formation substrate 31, and thesubstrate 19 (FIG. 3C).

As illustrated in FIG. 3C, the end portion of the bonding layer 17 ispreferably positioned inwardly from an end portion of the separationlayer 32. Alternatively, the end portion of the bonding layer 17 andthat of the separation layer 32 may overlap with each other.Accordingly, strong adhesion between the formation substrate 31 and thesubstrate 19 can be suppressed; thus, a decrease in yield of asubsequent separation process can be suppressed.

In the case where the bonding layer 17 is formed using a material withhigh fluidity, a partition 18 a illustrated in FIG. 3D is preferablyused to hold the bonding layer 17.

FIG. 3E illustrates an example of a top view in which the bonding layer17 and the partition 18 a are formed over the substrate 19. The bondinglayer 17 is provided inside the partition 18 a having a frame-likeshape.

As illustrated in FIG. 3F, a temporary sealing layer 18 b may beprovided outside the partition 18 a.

FIG. 3G illustrates an example of a top view in which the bonding layer17, the partition 18 a, and the temporary sealing layer 18 b are formedover the substrate 19. The bonding layer 17 is provided inside thepartition 18 a having a frame-like shape. The temporary sealing layer 18b having a frame-like shape is provided outside the partition 18 ahaving a frame-like shape.

The bonding layer 17, the partition 18 a, and the temporary sealinglayer 18 b may be formed over either the formation substrate 31 or thesubstrate 19. All of the bonding layer 17, the partition 18 a, and thetemporary sealing layer 18 b may be formed over one of the substrates.Alternatively, the bonding layer 17 and the partition 18 a may be formedover one substrate and the temporary sealing layer 18 b may be formedover the other substrate.

The thickness of the partition 18 a and that of the temporary sealinglayer 18 b are each greater than or equal to 1 μm and less than or equalto 200 μm, preferably greater than or equal to 1 μm and less than orequal to 100 μm, further preferably greater than or equal to 1 μm andless than or equal to 50 μm, for example.

There is no particular limitation on methods for forming the partition18 a and the temporary sealing layer 18 b; for example, a dropletdischarge method, a printing method (such as a screen printing method oran offset printing method), a coating method such as a spin coatingmethod or a spray coating method, a dipping method, a dispenser method,a nanoimprint method, or the like can be employed.

A variety of materials that can be used for the bonding layer 17 can beused for the partition 18 a and the temporary sealing layer 18 b.

The partition 18 a is preferably formed using a material having higherviscosity than the bonding layer 17. The partition 18 a is preferablyformed using a material with high viscosity, in which case entry ofimpurities such as moisture from the air can be inhibited.

[S2-5: Cure the Bonding Layer]

Next, the bonding layer 17 is cured.

Furthermore, at least part of the temporary sealing layer 18 b may becured. When the light-emitting device is exposed to an air atmosphere,atmospheric pressure is applied to the formation substrate 31 and thesubstrate 19. As a result, the reduced-pressure state of the spacesurrounded by the temporary sealing layer 18 b, the formation substrate31, and the substrate 19 is maintained. Thus, impurities such asmoisture in the air can be prevented from entering the light-emittingdevice.

Furthermore, the partition 18 a may be cured. By curing the partition 18a, the light-emitting device in which the light-emitting element 15 issealed with the bonding layer 17, the partition 18 a, and the substrate19 can be manufactured.

There is no particular limitation on the order of curing the bondinglayer 17, the partition 18 a, and the temporary sealing layer 18 b.

As for subsequent steps, there are three manufacturing methods 2-A, 2-B,and 2-C.

First, FIG. 4A illustrates a flowchart of the manufacturing method 2-A.The manufacturing method 2-A is an example of changing the shape of thelight-emitting device before separating the formation substrate 31.

[S2-6A: Apply Pressure to the Non-Light-Emitting Portion while Heatingthe Bonding Layer]

Next, while the bonding layer 17 is heated, pressure is applied to atleast a portion of a non-light-emitting portion 26 by using a member 21a having a projection (FIG. 4B).

In FIG. 4B and the like, a portion where the light-emitting element 15is provided over the formation substrate 31 is illustrated as alight-emitting portion 25, and a portion other than the light-emittingportion 25 is illustrated as the non-light-emitting portion 26.

The bonding layer 17 becomes thinner at the portion to which pressure isapplied than at the other portion (FIG. 4C). It can also be said thatthe gap between the formation substrate 31 and the substrate 19 becomesnarrower in a portion of the non-light-emitting portion 26 than in thelight-emitting portion 25.

[S2-7A: Separate the Formation Substrate]

Next, the formation substrate 31 and the insulating layer 13 areseparated from each other. Here, a separation starting point (alsoreferred to as a trigger) for separation of the formation substrate 31is preferably formed. The separation starting point is formed in aregion where the bonding layer 17 and the separation layer 32 overlapwith each other.

The separation starting point can be formed through laser lightirradiation, etching of the separation layer using a gas, a solution, orthe like, division of the substrate, or mechanical removal such asmaking a cut with a sharp cutting tool such as a knife, a scalpel, or acutter, for example. Formation of the separation starting pointfacilitates separation of the separation layer and the layer to beseparated, which is preferable.

For example, when the substrate 19 can be divided with a cutting tool orthe like, the separation starting point can be formed by making a cut inthe substrate 19, the bonding layer 17, and the insulating layer 13.

In the case where laser light irradiation is employed, a region wherethe bonding layer 17 in a cured state, the insulating layer 13, and theseparation layer 32 overlap with one another is preferably irradiatedwith the laser light. Although laser light irradiation may be performedfrom either substrate side, it is preferably performed from theformation substrate 31 side in which the separation layer 32 isprovided, in order to prevent the light-emitting element, thetransistor, or the like from being irradiated with scattered light. Notethat a material that transmits the laser light is used for the substrateon the side where laser light irradiation is performed.

The insulating layer 13 is cracked (or broken), whereby the separationstarting point can be formed. At this time, not only the insulatinglayer 13 but also part of the separation layer 32 and the bonding layer17 may be removed. Laser light irradiation enables part of the filmsincluded in the insulating layer 13, the separation layer 32, or thebonding layer 17 to be dissolved, evaporated, or thermally broken.

It is preferable that in the separation step, force of separating theinsulating layer 13 and the separation layer 32 be concentrated at theseparation starting point; therefore, it is preferable to form theseparation starting point not at the center portion of the bonding layer17 in a cured state but in the vicinity of the end portion. It isparticularly preferable to form the separation starting point in thevicinity of the corner portion compared to the vicinity of the sideportion among the vicinities of the end portion. In such a case wherethe separation starting point is formed in a position not overlappingwith the bonding layer 17, it is preferable that the position at whichthe separation starting point is formed be in a short distance from thebonding layer 17, whereby the separation layer 32 and the insulatinglayer 13 can be separated surely; specifically, it is preferable thatthe separation starting point be formed in a distance from the endportion of the bonding layer 17 within 1 mm.

There is no particular limitation on lasers used to form the separationstarting point. For example, a continuous wave laser or a pulsed lasercan be used. A condition for laser light irradiation such as frequency,power density, energy density, or beam profile is controlled asappropriate in consideration of thicknesses, materials, or the like ofthe formation substrate 31 and the separation layer 32.

Laser light is preferably employed, in which case the substrate does notneed to be, for example, cut to form the separation starting point andgeneration of dust or the like can be suppressed. In addition, the timetaken to form the separation starting point can be shortened. Moreover,the formation substrate 31 can be reused easily because dust thatremains on the surface of the formation substrate 31 can be reduced.Furthermore, laser light results in low cost and can be easily appliedto mass production because it does not cause wear of a sharp cuttingtool such as a cutter. Separation can be started by pulling the endportion of either of the substrates and therefore can be easily appliedto mass production.

Then, the insulating layer 13 and the formation substrate 31 areseparated from each other from the formed separation starting point. Atthis time, one of the substrates is preferably fixed to a suction stageor the like. For example, the formation substrate 31 may be fixed to thesuction stage to separate the insulating layer 13 from the formationsubstrate 31. Alternatively, the substrate 19 may be fixed to a suctionstage to separate the formation substrate 31 from the substrate 19.

For example, the insulating layer 13 and the formation substrate 31 maybe separated from the separation starting point by mechanical force(e.g., a separation process with a human hand or a jig, or a separationprocess by rotation of a roller).

Alternatively, the formation substrate 31 and the insulating layer 13may be separated by filling the interface between the separation layer32 and the insulating layer 13 with a liquid such as water. A portionbetween the separation layer 32 and the insulating layer 13 absorbs aliquid through capillarity action, so that separation occurs easily.Furthermore, an adverse effect on the functional element included in theinsulating layer 13 due to static electricity caused at separation(e.g., a phenomenon in which a semiconductor element is damaged bystatic electricity) can be suppressed. Note that the liquid can besprayed in the form of mist or steam. As the liquid, pure water, anorganic solvent, a neutral, alkaline, or acid aqueous solution, anaqueous solution in which a salt is dissolved, or the like can be used.

Note that after the separation, the bonding layer 17, the partition 18a, the temporary sealing layer 18 b, and the like which do notcontribute to attachment between the insulating layer 13 and thesubstrate 19 and which remain over the substrate 19 may be removed. Bysuch removal, an adverse effect on the functional element in asubsequent step (e.g., entry of impurities) can be preferablysuppressed. For example, an unnecessary resin can be removed by wipingor cleaning.

[S2-8A: Attach a Substrate]

Next, to the insulating layer 13 that is exposed by separation of theformation substrate 31, a substrate 11 is attached with the use of abonding layer 12. A step of, for example, cutting an end portion of thelight-emitting device is performed, so that the light-emitting deviceillustrated in FIG. 4D can be manufactured.

A variety of materials that can be used for the bonding layer 17 can beused for the bonding layer 12. Any of the above-described materials canbe used for the substrate 11, and it is particularly preferable that aflexible substrate be used.

In the above-described manner, the light-emitting device of oneembodiment of the present invention can be manufactured.

Next, FIG. 5A illustrates a flowchart of the manufacturing methods 2-Band 2-C. The manufacturing methods 2-B and 2-C are examples of changingthe shape of the light-emitting device after separating the formationsubstrate 31. The manufacturing method 2-B is an example of changing theshape of the light-emitting device after attaching the substrate 11. Themanufacturing method 2-C is an example of changing the shape of thelight-emitting device before attaching the substrate 11.

[S2-6B: Separate the Formation Substrate]

In each of the manufacturing methods 2-B and 2-C, the formationsubstrate 31 and the insulating layer 13 are separated from each otherafter the bonding layer 17 is cured. The step S2-7A can be referred tofor details of the separation method. By this step, the insulating layer13 is exposed (FIG. 5B).

Since the formation substrate 31 is separated before the shape of thelight-emitting device is changed, a decrease in yield of separation dueto the change in shape of the light-emitting device can be suppressed.

[S2-7B: Attach the Substrate]

In the manufacturing method 2-B, the substrate 11 is then attached tothe insulating layer 13 with the bonding layer 12.

In many cases, both sides of a film that can be favorably used as thesubstrate 11 are provided with separation films (also referred to asseparate films or release films). When the substrate 11 and theinsulating layer 13 are attached to each other, only one of theseparation films provided on the substrate 11 is separated. Leaving theother separation film facilitates transportation or processing in alater step. In some cases, the separation film is preferably separatedbefore the step of changing the shape of the light-emitting device,depending on physical properties of the separation film (such as thecoefficient of linear expansion) and conditions for changing the shapeof the light-emitting device (such as temperature and pressure).

[S2-8B: Apply Pressure to the Non-Light-Emitting Portion while Heatingthe Bonding Layer]

Next, while the bonding layer 17 is heated, pressure is applied to atleast a portion of the non-light-emitting portion 26 by using a member21 b having a projection (FIG. 5C).

In FIG. 5C and the like, a portion where the light-emitting element 15is provided over the substrate 11 is illustrated as the light-emittingportion 25, and a portion other than the light-emitting portion 25 isillustrated as the non-light-emitting portion 26.

The bonding layer 17 becomes thinner at the portion to which pressure isapplied than at the other portion (FIG. 5D). It can also be said thatthe gap between the substrate 11 and the substrate 19 becomes narrowerin a portion of the non-light-emitting portion 26 than in thelight-emitting portion 25.

Although FIG. 5C illustrates an example of applying pressure to thenon-light-emitting portion 26 from the substrate 11 side with the use ofthe member 21 b having the projection, one embodiment of the presentinvention is not limited to this example.

FIG. 6A illustrates an example of applying pressure to thenon-light-emitting portion from both the substrate 11 side and thesubstrate 19 side with the use of the members 21 a and 21 b having theprojections. Also in this case, the bonding layer 17 becomes thinner atthe portion to which pressure is applied of the non-light-emittingportion than at the other portion (FIG. 6B). The projections of themembers 21 a and 21 b do not necessarily overlap with each other withthe light-emitting device provided therebetween.

In the above-described manner, the light-emitting device of oneembodiment of the present invention can be manufactured.

[S2-7C: Apply Pressure to the Non-Light-Emitting Portion while Heatingthe Bonding Layer]

In the manufacturing method 2-C, after the step S2-6B, while the bondinglayer 17 is heated, pressure is applied to at least a portion of thenon-light-emitting portion 26 by using the member 21 b having theprojection (FIG. 5E).

In FIG. 5E, a portion where the light-emitting element 15 is providedover the insulating layer 13 is illustrated as the light-emittingportion 25, and a portion other than the light-emitting portion 25 isillustrated as the non-light-emitting portion 26.

FIG. 5E illustrates an example in which only the insulating layer 13 islocated between the bonding layer 17 and the member 21 b having theprojection. Pressure can be applied to the bonding layer 17 moredirectly than in the step S2-8B or the like in which pressure is appliedto the bonding layer 17 through the substrate 11 or the like. Therefore,by this step, the bonding layer 17 can be surely made thinner than atthe other portion.

[S2-8C: Attach the Substrate]

The substrate 11 is then attached to the insulating layer 13 with thebonding layer 12. A step of, for example, cutting an end portion of thelight-emitting device is performed, so that the light-emitting deviceillustrated in FIG. 5F can be manufactured.

The bonding layer 17 is thinner at the portion to which pressure isapplied than at the other portion (FIG. 5F). It can also be said thatthe gap between the substrate 11 and the substrate 19 is narrower in aportion of the non-light-emitting portion than in the light-emittingportion.

In the manufacturing method 2-C, the substrate 11 is attached after theshape of the bonding layer 17 is changed. Therefore, the physicalproperties of the substrate 11 (such as the coefficient of linearexpansion) and the physical properties of the bonding layer 12 (such asthe glass transition temperature) are not limited by conditions (such astemperature and pressure) for the step of changing the shape of thelight-emitting device.

Although FIG. 5E illustrates an example of applying pressure to thenon-light-emitting portion 26 from the insulating layer 13 side with theuse of the member 21 b having the projection, one embodiment of thepresent invention is not limited to this example.

FIG. 6C illustrates an example of applying pressure to thenon-light-emitting portion from both the insulating layer 13 side andthe substrate 19 side with the use of the members 21 a and 21 b havingthe projections. Also in this case, the bonding layer 17 becomes thinnerat the portion to which pressure is applied of the non-light-emittingportion than at the other portion (FIG. 6D). It is preferable that theprojections of the members 21 a and 21 b partly overlap with each otherwith the light-emitting device provided therebetween. When theprojections of the members 21 a and 21 b at least partly overlap witheach other with the light-emitting device provided therebetween, a muchthinner portion than the light-emitting portion can be formed in thenon-light-emitting portion.

In the above-described manner, the light-emitting device of oneembodiment of the present invention can be manufactured.

<Manufacturing Method 3>

FIG. 7 illustrates a flowchart of the manufacturing method 3 of thelight-emitting device.

[S3-1: Form a First Separation Layer Over a First Formation Substrate]

A separation layer 32 is formed over a formation substrate 31.

[S3-2: Form a First Layer to be Separated Over the first SeparationLayer]

Next, a layer to be separated is formed over the separation layer 32.FIG. 8A illustrates an example in which an insulating layer 13 over theseparation layer 32 and a light-emitting element 15 over the insulatinglayer 13 are formed as the layer to be separated.

[S3-3: Form a Second Separation Layer Over a Second Formation Substrate]

A separation layer 52 is formed over a formation substrate 51. A varietyof materials that can be used for the formation substrate 31 can be usedfor the formation substrate 51. A variety of materials that can be usedfor the separation layer 32 can be used for the separation layer 52.

[S3-4: Form a Second Layer to be Separated Over the Second SeparationLayer]

Next, a layer to be separated is formed over the separation layer 52.FIG. 8B illustrates an example in which an insulating layer 53 over theseparation layer 52 and a coloring layer 55 over the insulating layer 53are formed as the layer to be separated.

The layer to be separated over the separation layer 52 is not limited tothe coloring layer 55, and a light-blocking layer, a touch sensor, orthe like may be formed as the layer to be separated.

There is no particular limitation on the order of the step S3-1 and thestep S3-3. Either step may be performed first, or the two steps may beperformed at the same time. The same applies to the order of the stepS3-2 and the step S3-4.

[S3-5: Form a Bonding Layer]

Next, a bonding layer 17 is formed over the formation substrate 31 orthe formation substrate 51.

The bonding layer 17 is preferably formed in such a manner that itoverlaps with the separation layer 32, the separation layer 52, theinsulating layer 13, and the insulating layer 53 in the next step S3-6in which the formation substrate 31 and the formation substrate 51 aremade to overlap each other. In that case, the yield of separation ofeach of the formation substrates 31 and 51 can be increased.

In an example described in this embodiment, the bonding layer 17, apartition 18 a, and a temporary sealing layer 18 b are formed (see across-sectional view in FIG. 8C illustrating the next step).

[S3-6: Overlap the Pair of Substrates]

Next, the formation substrate 31 and the formation substrate 51 areoverlapped such that the light-emitting element 15 is positioned in aspace surrounded by the bonding layer 17, the formation substrate 31,and the formation substrate 51 (FIG. 8C).

Although the separation layer 32 and the separation layer 52 have thesame size in FIG. 8C, the two separation layers may have differentsizes.

An end portion of the bonding layer 17 is preferably positioned inwardlyfrom at least an end portion of either the separation layer 32 or theseparation layer 52, specifically inward from an end portion of theseparation layer on the side of the formation substrate which isintended to be separated first. Accordingly, strong adhesion between theformation substrate 31 and the formation substrate 51 can be suppressed;thus, a decrease in yield of a subsequent separation process can besuppressed. FIG. 8C illustrates an example in which the end portion ofthe bonding layer 17 is located inwardly from the end portions of boththe separation layer 32 and the separation layer 52.

[S3-7: Cure the Bonding Layer]

Next, the bonding layer 17 is cured. Furthermore, at least one of thepartition 18 a and the temporary sealing layer 18 b may be cured.

Application of pressure to a non-light-emitting portion while thebonding layer 17 is heated may be performed at any timing after the stepS3-7. Note that the timing might affect the level of yield of theseparation step, the changeability in shape of the bonding layer 17, andthe like. Therefore, the step S3-7 is preferably followed by a stepS3-8.

[S3-8: Separate the First Formation Substrate]

Next, the formation substrate 31 and the insulating layer 13 areseparated from each other. The step S2-7A can be referred to for detailsof the separation method. By this step, the insulating layer 13 isexposed.

Since the formation substrate 31 is separated before the shape of thelight-emitting device is changed, a decrease in yield of separation dueto the change in shape of the light-emitting device can be suppressed.

As for subsequent steps, there are four manufacturing methods 3-A, 3-B,3-C, and 3-D.

First, FIG. 7 illustrates a flowchart of the manufacturing methods 3-Aand 3-B. The manufacturing methods 3-A and 3-B are examples of changingthe shape of the light-emitting device before separating the formationsubstrate 51. The manufacturing method 3-A is an example of changing theshape of the light-emitting device after attaching the substrate 11. Themanufacturing method 3-B is an example of changing the shape of thelight-emitting device before attaching the substrate 11.

[S3-9A: Attach the First Substrate]

In the manufacturing method 3-A, the substrate 11 is then attached tothe insulating layer 13 with a bonding layer 12. At that time, apartition 18 c surrounding the bonding layer 12 and a temporary sealinglayer 18 d having a frame-like shape outside the partition 18 c may beformed (see a cross-sectional view in FIG. 8D illustrating the nextstep).

[S3-10A: Apply Pressure to the Non-Light-Emitting Portion while Heatingthe Bonding Layer]

Next, while the bonding layer 17 is heated, pressure is applied to atleast a portion of the non-light-emitting portion 26 by using a member21 b having a projection (FIG. 8D).

In FIG. 8D, a portion where the light-emitting element 15 is providedover the insulating layer 13 is illustrated as a light-emitting portion25, and a portion other than the light-emitting portion 25 isillustrated as the non-light-emitting portion 26.

The bonding layer 17 becomes thinner at the portion to which pressure isapplied than at the other portion (FIG. 8D). It can also be said thatthe gap between the substrate 11 and the formation substrate 51 becomesnarrower in a portion of the non-light-emitting portion 26 than in thelight-emitting portion 25.

[S3-11A: Separate the Second Formation Substrate]

Next, the formation substrate 51 and the insulating layer 53 areseparated from each other. The step S2-7A can be referred to for detailsof the separation method. By this step, the insulating layer 53 isexposed.

[S3-12A: Attach a Second Substrate]

A substrate 19 is then attached to the insulating layer 53 with abonding layer 16. A step of, for example, cutting an end portion of thelight-emitting device is performed, so that the light-emitting deviceillustrated in FIG. 8E can be manufactured.

In the above-described manner, the light-emitting device of oneembodiment of the present invention can be manufactured.

[S3-9B: Apply Pressure to the Non-Light-Emitting Portion while Heatingthe Bonding Layer]

In the manufacturing method 3-B, after the step S3-8, while the bondinglayer 17 is heated, pressure is applied to at least a portion of thenon-light-emitting portion 26 by using the member 21 b having theprojection (FIG. 9A).

In FIG. 9A, a portion where the light-emitting element 15 is providedover the insulating layer 13 is illustrated as the light-emittingportion 25, and a portion other than the light-emitting portion 25 isillustrated as the non-light-emitting portion 26.

FIG. 9A illustrates an example in which only the insulating layer 13 islocated between the bonding layer 17 and the member 21 b having theprojection. Pressure can be applied to the bonding layer 17 moredirectly than in the step 53-10A or the like in which pressure isapplied to the bonding layer 17 through the substrate 11 or the like.Therefore, by this step, the bonding layer 17 can be surely made thinnerthan at the other portion.

[S3-10B: Attach the First Substrate]

The substrate 11 is then attached to the insulating layer 13 with thebonding layer 12 (FIG. 9B). As illustrated in FIG. 9B, the partition 18c surrounding the bonding layer 12 and the temporary sealing layer 18 dhaving a frame-like shape outside the partition 18 c may be formed.

[S3-11A: Separate the Second Formation Substrate]

Next, the formation substrate 51 and the insulating layer 53 areseparated from each other. The step S2-7A can be referred to for detailsof the separation method. By this step, the insulating layer 53 isexposed.

[S3-12A: Attach the Second Substrate]

The substrate 19 is then attached to the insulating layer 53 with thebonding layer 16. A step of, for example, cutting an end portion of thelight-emitting device is performed, so that the light-emitting deviceillustrated in FIG. 9C can be manufactured.

In the above-described manner, the light-emitting device of oneembodiment of the present invention can be manufactured.

Note that a spacer 59 illustrated in FIG. 9D or 9E may be provided inthe light-emitting device in order to decrease the minimum thickness ofthe bonding layer 17. The spacer 59 is provided in thenon-light-emitting portion. The spacer 59 may be formed over theinsulating layer 53 (see FIG. 9D), over the insulating layer 13 (seeFIG. 9E), or over both the insulating layer 53 and the insulating layer13. The portion to which pressure is applied by using the member havingthe projection preferably overlaps with the spacer 59. In that case, theminimum thickness of the bonding layer 17 can be significantlydecreased.

At least a surface of the spacer 59 is preferably formed using aninorganic material. For example, the entire spacer 59 may be formedusing an inorganic material. As illustrated in FIG. 9E, the spacer 59preferably has a stacked-layer structure including a thick organic filmand an inorganic film covering a top surface and a side surface of theorganic film. In the case where the spacer 59 is partly formed using anorganic material, the height (the thickness) of the spacer 59 can bemore easily increased than in the case where the entire spacer 59 isformed using an inorganic material. In addition, the time needed to formthe spacer 59 can be shortened. The spacer 59 preferably has aninsulating property.

Next, FIG. 10A illustrates a flowchart of the manufacturing methods 3-Cand 3-D. The manufacturing methods 3-C and 3-D are examples of changingthe shape of the light-emitting device after separating both theformation substrate 31 and the formation substrate 51. The manufacturingmethod 3-C is an example of changing the shape of the light-emittingdevice after attaching the substrate 19. The manufacturing method 3-D isan example of changing the shape of the light-emitting device beforeattaching the substrate 19.

[S3-10C: Separate the Second Formation Substrate]

In each of the manufacturing methods 3-C and 3-D, the substrate 51 andthe insulating layer 53 are separated from each other after thesubstrate 11 is attached in the step S3-9A. The step S2-7A can bereferred to for details of the separation method. By this step, theinsulating layer 53 is exposed.

Since the formation substrate 51 as well as the substrate 31 isseparated before the shape of the light-emitting device is changed, adecrease in yield of each separation step due to the change in shape ofthe light-emitting device can be suppressed.

Note that FIG. 10B illustrates an example of attaching the substrate 11in the step S3-9A by using only the bonding layer 12 without using thepartition 18 a and without using the temporary sealing layer 18 b. Inthe end portion of the light-emitting device, there is a portion wherethe substrate 11 and the formation substrate 51 are attached to eachother with the bonding layer 12 without the separation layer 52 providedtherebetween. In such a case, a separation starting point having aframe-like shape is preferably formed by making a cut in the substrate11 with a cutting tool or the like. The separation starting point can beformed by making the cut from the substrate 11 to the insulating layer53. For example, the cut is preferably made from portions indicated byarrows in FIG. 10B.

[S3-11C: Attach the Second Substrate]

In the manufacturing method 3-C, the substrate 19 is then attached tothe insulating layer 53 with the bonding layer 16.

[S3-12C: Apply Pressure to the Non-Light-Emitting Portion while Heatingthe Bonding Layer]

Next, while the bonding layer 17 is heated, pressure is applied to atleast a portion of the non-light-emitting portion 26 by using a member21 a having a projection (FIG. 11A).

In FIG. 11A, a portion where the light-emitting element 15 is providedover the insulating layer 13 is illustrated as the light-emittingportion 25, and a portion other than the light-emitting portion 25 isillustrated as the non-light-emitting portion 26.

The bonding layer 17 becomes thinner at the portion to which pressure isapplied than at the other portion (FIG. 11B). It can also be said thatthe gap between the substrate 11 and the substrate 19 becomes narrowerin the non-light-emitting portion 26 than in the light-emitting portion25.

In the above-described manner, the light-emitting device of oneembodiment of the present invention can be manufactured.

[S3-11D: Apply Pressure to the Non-Light-Emitting Portion while Heatingthe Bonding Layer]

In the manufacturing method 3-D, after the step S3-10C, while thebonding layer 17 is heated, pressure is applied to at least a portion ofthe non-light-emitting portion 26 by using the member 21 a having theprojection (FIG. 11C).

In FIG. 11C, a portion where the light-emitting element 15 is providedover the insulating layer 13 is illustrated as the light-emittingportion 25, and a portion other than the light-emitting portion 25 isillustrated as the non-light-emitting portion 26.

FIG. 11C illustrates an example in which only the insulating layer 53 islocated between the bonding layer 17 and the member 21 a having theprojection. Pressure can be applied to the bonding layer 17 moredirectly than in the step S3-12C or the like in which pressure isapplied to the bonding layer 17 through the substrate 19 or the like.Therefore, by this step, the bonding layer 17 can be surely made thinnerthan at the other portion.

[S3-12D: Attach the Second Substrate]

The substrate 19 is then attached to the insulating layer 53 with thebonding layer 16 (FIG. 11D).

In the above-described manner, the light-emitting device of oneembodiment of the present invention can be manufactured.

<Example of a Top View of the Light-Emitting Device>

In the light-emitting device of one embodiment of the present invention,a thin region is formed in at least a portion of the non-light-emittingportion. FIGS. 12A to 12H each illustrate a light-emitting deviceincluding a pair of substrates (a flexible substrate 251 and a flexiblesubstrate 259). An FPC 808 is connected to the light-emitting device.The FPC 808 is electrically connected to an external connectionelectrode (not illustrated) over the flexible substrate 251.

FIG. 12A illustrates an example in which a thin region 258 is formed ina frame-like shape along four sides of the light-emitting device. Thethin region 258 is provided outside a light-emitting portion 804 and adriver circuit portion 806.

FIG. 12B illustrates an example in which the thin region 258 is formedalong three sides of the light-emitting device. In FIG. 12B, thenon-light-emitting portion in a portion where the driver circuit portion806 and the external connection electrode are provided (on the rightside of the light-emitting device in FIG. 12B) does not have the thinregion 258. The shortest distance from the side of the light-emittingportion 804 that is adjacent to the driver circuit portion 806 to an endportion of the light-emitting device is longer than the shortestdistance from the other sides of the light-emitting portion 804 to otherend portions of the light-emitting device; therefore, on the side of thelight-emitting device on which the driver circuit portion 806 isprovided, impurities are unlikely to reach the light-emitting element orthe like. In that case, the non-light-emitting portion does notnecessarily have a portion whose thickness is smaller than that of thelight-emitting portion. In the above manner, the element included in thedriver circuit portion 806 can be prevented from deteriorating becauseof bending. Moreover, the external connection electrode and the FPC 808can be electrically connected to each other reliably. Damage to theelements included in the driver circuit portion 806 can be inhibitedwhen pressure is applied at the time of formation of a depression.

Note that the depression may be formed so as to overlap with the drivercircuit portion 806 in the case where there is no adverse influence onthe reliability of the elements. For example, the flexible substrate 259may have a depression in a portion that overlaps with a scan line drivercircuit or a signal line driver circuit. The flexible substrate 259 mayhave a depression in a portion that overlaps with a contact portionbetween an electrode (an anode or a cathode) of the light-emittingelement and a wiring. A thin region may also be formed in a portion ofthe light-emitting portion as long as providing the thin region in theportion does not adversely affect display quality; for example, a thinregion may be formed to overlap with a dummy pixel or an end portion ofa color filter.

FIG. 12C illustrates an example in which the thin region 258 is formedalong two sides of the light-emitting device.

FIG. 12D illustrates an example in which the thin region 258 is formedalong one side of the light-emitting device.

FIG. 12E illustrates an example in which the thin region 258 is formedin a frame-like shape along four sides of the light-emitting device. Theexample illustrated in FIG. 12E differs from the example in FIG. 12A inthat the thin region 258 is provided between the light-emitting portion804 and the driver circuit portion 806.

FIG. 12F illustrates an example in which the thin region 258 is formedin a frame-like shape along four sides of the light-emitting device. Theexample illustrated in FIG. 12F differs from the example in FIG. 12A inthat a plurality of thin regions 258 are provided at intervals.

FIGS. 12G and 12H each illustrate an example of a light-emitting devicein which the light-emitting portion 804 has a circular top-view shape.The light-emitting portion 804 does not necessarily have a polygonaltop-view shape and may have any of a variety of top-view shapes such ascircular and elliptical shapes.

The light-emitting device does not necessarily have a polygonal top-viewshape and may have any of a variety of top-view shapes such as circularand elliptical shapes. The light-emitting device in each of FIGS. 12Gand 12H has a top-view shape including both a curved portion and alinear portion.

The thin region 258 may have any of a variety of top-view shapes such aspolygonal, circular, and elliptical shapes. The thin region 258 in FIG.12G includes both a curved portion and a linear portion. In FIG. 12H,the thin region 258 has a circular shape.

<Example of a Method for Applying Pressure with a Hot Press>

A method for applying pressure in the light-emitting device in the stepS1-5 or the like will be described.

FIGS. 13A and 13B each illustrate a hot press that includes an upperplate 2000 a and a lower plate 2000 b. The hot press has a heat sourceand heats one or both of the upper plate 2000 a and the lower plate 2000b.

First, the light-emitting device 10, a jig, a cushioning material, andthe like are provided between the upper plate 2000 a and the lower plate2000 b of the hot press.

A structure in FIG. 13A will be described. A substrate 2100 is providedover the lower plate 2000 b with a cushioning material 2005 b positionedtherebetween. The substrate 2100 is an example of a press jig. Thelight-emitting device 10 (see FIG. 1D) is placed over the substrate2100. Over the light-emitting device 10, the member 21 a having theprojection is provided. The projection is in contact with the substrate19. The projection overlaps with the non-light-emitting portion of thelight-emitting device 10. The member 21 a having the projection is anexample of a press jig. A cushioning material 2005 a is provided betweenthe member 21 a having the projection and the upper plate 2000 a.

As illustrated in FIG. 13B, a cushioning material 2005 c may be providedbetween the member 21 a having the projection and the light-emittingdevice 10. Furthermore, as illustrated in FIG. 13B, a cushioningmaterial 2005 d may be provided between the substrate 2100 and thelight-emitting device 10. Providing the cushioning material can reducedamage to the light-emitting device 10 by local pressure application tothe light-emitting device 10. Providing no cushioning material allows anextremely thin portion to be formed in the bonding layer 17 by localpressing of the light-emitting device 10. Whether each cushioningmaterial is used or not is determined depending on the structure of thelight-emitting device 10, pressing conditions (such as load or time), orthe like.

The hot press preferably includes an alignment mechanism. This enablesthe depression to be formed at a desired position of the light-emittingdevice 10. The hot press preferably includes a mechanism for fixing thelight-emitting device 10, such as a suction mechanism. This enables thelight-emitting device 10 to be fixed at a position relative to thedepression.

The member 21 a and the projection can be formed using a material thatcan withstand applied pressure. A mold having a projection may be usedas the member 21 a having the projection. The mold can be formed usingthe material that can be used for the substrate. For example, the moldcan be formed using a resin, glass, a metal, or an alloy. The projectioncan be formed over the substrate with the use of an organic materialsuch as a resin or an inorganic material such as a metal. There is nolimitation on methods for forming the projection, and a sputteringmethod, a CVD method, a coating method, a printing method, a dropletdischarge method, or a dispensing method may be used, for example. Theprojection can also be formed by curing an adhesive provided over thesubstrate.

FIGS. 14A to 14F each illustrate an example of a top-view shape of amember 21 having a projection.

A projection 22 may be formed in a frame-like shape as illustrated inFIGS. 14A, 14B, 14D, 14E, and 14F. The projection 22 is not necessarilypositioned at an edge of the member 21 (FIG. 14A). Alternatively, theprojection 22 may extend to the edge of the member 21 (FIG. 14B). Theprojection 22 may be provided along three of four sides of the member 21having the projection (FIG. 14C). Alternatively, the projection 22 maybe provided along two sides or one side of the member 21. Note that theprojection 22 is not necessarily parallel to any of the sides of themember 21. The number of projections 22 may be one or more. FIG. 14Dillustrates an example in which four sides are provided with respectiveprojections 22. FIG. 14E illustrates an example in which a plurality ofprojections 22 are provided at intervals along each of four sides. FIG.14F illustrates a member 21 having two projections that are a projection22 a having a frame-like shape and a projection 22 b having a frame-likeshape inside the projection 22 a.

Next, in a state illustrated in FIG. 13A or 13B, pressure is gentlyapplied to the light-emitting device 10 to fix the light-emitting device10.

Then, the light-emitting device 10 is heated using the heat source. Forexample, the temperature of the heat source is set higher than or equalto 80° C. and lower than or equal to 100° C.

Then, pressure is applied to the light-emitting device 10. Pressure isapplied to the light-emitting device 10 with the member 21 a having theprojection while the light-emitting device 10 is heated with the heatsource.

The load for the pressure application is not particularly limited. Theload may be, for example, greater than or equal to 0.5 t, greater thanor equal to 0.8 t, or greater than or equal to 1.0 t and less than orequal to 1.5 t, less than or equal to 2.0 t, or less than or equal to3.0 t. The heating temperature is not particularly limited and isdetermined depending on the glass transition temperature or the like ofmaterials used for the bonding layer 17 and the light-emitting element15. For example, the heating temperature may be higher than or equal to80° C., higher than or equal to 90° C., or higher than or equal to 100°C. and lower than or equal to 120° C., lower than or equal to 150° C.,or lower than or equal to 200° C. The time for the pressure applicationwhile the light-emitting device 10 is heated is not particularlylimited.

A width W2 of the depression formed in the substrate 19 of thelight-emitting device 10 is larger than a width W1 of the projection(FIG. 14G). For example, the width W2 is larger than the width W1 andsmaller than or equal to 1.5 times, smaller than or equal to 2 times, orsmaller than or equal to 3 times the width W1. The width W2 may be morethan 3 times the width W1. The depth of the depression formed in thesubstrate 19 of the light-emitting device 10 is smaller than or equal toa height d of the projection. The width W2 is, for example, larger thanor equal to, larger than or equal to 5 times, or larger than or equal to10 times and smaller than or equal to 20 times, smaller than or equal to50 times, or smaller than or equal to 100 times the depth of thedepression.

For example, the depth of the depression can be greater than or equal to0.01 mm, greater than or equal to 0.05 mm, or greater than or equal to0.1 mm and less than or equal to 2 mm, less than or equal to 1 mm, orless than or equal to 0.5 mm. The width W2 can be greater than or equalto 0.1 mm, greater than or equal to 1 mm, or greater than or equal to 1cm and less than or equal to 10 cm, less than or equal to 5 cm, or lessthan or equal to 3 cm. The width W2 is preferably larger than 0 timesthe width of the non-light-emitting portion and smaller than or equal tothe width of the non-light-emitting portion, and may be larger than orequal to 0.2 times and smaller than or equal to 0.8 times, or largerthan or equal to 0.4 times and smaller than or equal to 0.6 times thewidth of the non-light-emitting portion. Note that the width W2 is notnecessarily the width of the depression and may be the width of theregion thinner than the light-emitting portion.

After a certain period of heating and pressure application, the bondinglayer 17 is cured by performing cooling while continuing the pressureapplication. Therefore, the hot press preferably includes both a heatingmechanism and a cooling mechanism. Cooling at the same time as pressureapplication makes it possible to maintain a state where thenon-light-emitting portion of the light-emitting device 10 has the thinportion.

As described above, the hot press can be used to form the thin portionin the non-light-emitting portion of the light-emitting device 10.

In the case where a plurality of light-emitting devices are manufacturedusing the substrate 11, the size of the member having the projection,the shape of the projection, or the like is preferably determineddepending on the number of light-emitting devices obtained using onesubstrate, the shape of a mask, or the like.

A member 21 illustrated in FIG. 15A has two projections 22 each having aframe-like shape. The two projections 22 each having a frame-like shapeare spaced apart from each other.

FIG. 15B illustrates an example of manufacturing two light-emittingdevices 10 using the substrate 11. With the use of the member 21 havingthe projections illustrated in FIG. 15A, pressure can be applied in onestep to the two light-emitting devices 10 in each of which thelight-emitting element 15 is formed over the substrate 11.

As described above, in the method for manufacturing the light-emittingdevice of one embodiment of the present invention, the shape is changedby pressure application at the same time as heating after the bondinglayer for sealing the light-emitting element is cured once. Accordingly,the shape of the bonding layer can be locally changed. Thus, thereliability of the light-emitting device can be improved, and a decreasein viewing-angle characteristics and a degradation of display quality ofthe light-emitting device can be suppressed.

In addition, in the manufacturing method of one embodiment of thepresent invention, pressure is applied to the bonding layer after theformation substrate for forming the light-emitting element or the likeis separated. Accordingly, a decrease in yield of the separation stepdue to the change in shape of the light-emitting device can besuppressed. Furthermore, in the manufacturing method of one embodimentof the present invention, pressure is applied to the bonding layer afterthe formation substrate is separated and before another substrate isattached. Accordingly, pressure can be applied to the bonding layer 17more directly than in the case where pressure is applied to the bondinglayer through the substrate. Thus, the bonding layer 17 can be surelymade thinner than at the other portion.

This embodiment can be combined with any other embodiment asappropriate.

Embodiment 2

In this embodiment, a light-emitting device of one embodiment of thepresent invention will be described with reference to drawings.

Light-emitting devices including EL elements are mainly described inthis embodiment as examples; however, one embodiment of the presentinvention is not limited to this example. The light-emitting devicesdescribed in this embodiment each have a region thinner than alight-emitting portion in a non-light-emitting portion and are thushighly reliable.

In this embodiment, the light-emitting device can have a structure inwhich subpixels of three colors of red (R), green (G), and blue (B), forexample, express one color; a structure in which subpixels of fourcolors of R, G, B, and white (W) express one color; a structure in whichsubpixels of four colors of R, G, B, and yellow (Y) express one color;or the like. There is no particular limitation on color elements, andcolors other than R, G, B, W, and Y may be used. For example, cyan,magenta, or the like may be used.

FIG. 16A is a plan view of a light-emitting device, and FIG. 16B is anexample of a cross-sectional view taken along the dashed-dotted lineD1-D2 in FIG. 16A. The light-emitting device illustrated in FIGS. 16Aand 16B is a top-emission light-emitting device using a color filtermethod.

The light-emitting device illustrated in FIG. 16A includes alight-emitting portion 804 and a driver circuit portion 806. Regionsother than the light-emitting portion 804 in the light-emitting devicecan be regarded as non-light-emitting portions. An FPC 808 is connectedto the light-emitting device. A depression 712 is provided along threesides of the light-emitting device. The depression 712 is a portionthinner than other portions of the light-emitting device.

The light-emitting device illustrated in FIG. 16B includes a firstflexible substrate 701, a first bonding layer 703, a first insulatinglayer 705, a first functional layer (a plurality of transistors, aconductive layer 857, an insulating layer 815, an insulating layer 817,a plurality of light-emitting elements, and an insulating layer 821), athird bonding layer 822, a second functional layer (a coloring layer 845and a light-blocking layer 847), a second insulating layer 715, a secondbonding layer 713, and a second flexible substrate 711. The thirdbonding layer 822, the second insulating layer 715, the second bondinglayer 713, and the second flexible substrate 711 transmit visible light.Light-emitting elements and transistors included in the light-emittingportion 804 and the driver circuit portion 806 are sealed with the firstflexible substrate 701, the second flexible substrate 711, and the thirdbonding layer 822.

The first insulating layer 705 and the first flexible substrate 701 areattached to each other with the first bonding layer 703. The secondinsulating layer 715 and the second flexible substrate 711 are attachedto each other with the second bonding layer 713. The first insulatinglayer 705 and the second insulating layer 715 are preferably highlyresistant to moisture. A light-emitting element 830, the transistors,and the like are preferably provided between a pair of insulating layerswhich are highly resistant to moisture, in which case impurities such asmoisture can be prevented from entering these elements, leading tohigher reliability of the light-emitting device.

The light-emitting portion 804 includes a transistor 820 and thelight-emitting element 830 over the first flexible substrate 701 withthe first bonding layer 703 and the first insulating layer 705 providedtherebetween. The light-emitting element 830 includes a lower electrode831 over the insulating layer 817, an EL layer 833 over the lowerelectrode 831, and an upper electrode 835 over the EL layer 833. Thelower electrode 831 is electrically connected to a source electrode or adrain electrode of the transistor 820. An end portion of the lowerelectrode 831 is covered with the insulating layer 821. The lowerelectrode 831 preferably reflects visible light. The upper electrode 835transmits visible light.

The light-emitting portion 804 includes the coloring layer 845overlapping with the light-emitting element 830 and the light-blockinglayer 847 overlapping with the insulating layer 821. The space betweenthe light-emitting element 830 and the coloring layer 845 is filled withthe third bonding layer 822.

The insulating layer 815 has an effect of inhibiting diffusion ofimpurities to a semiconductor included in the transistor. As theinsulating layer 817, an insulating layer having a planarizationfunction is preferably selected in order to reduce surface unevennessdue to the transistor.

The light-emitting device illustrated in FIG. 16B can be manufactured bythe manufacturing method 3 in Embodiment 1. The first insulating layer705 and the first functional layer are formed as one layer to beseparated. The second insulating layer 715 and the second functionallayer are formed as the other layer to be separated.

The insulating layer 817 is preferably provided in the entire area ofthe light-emitting device as illustrated in FIG. 16B, in which case theyield of the separation step can be increased.

In the case where an organic material is used for the insulating layer817, an impurity such as moisture outside the insulating layer 817 mightenter the light-emitting element 830 or the like through the insulatinglayer 817. Deterioration of the light-emitting element 830 due to theentry of an impurity leads to deterioration of the light-emittingdevice. Thus, as illustrated in FIG. 17A, it is preferable that anopening which reaches an inorganic film (here, the insulating layer 815)be formed in the insulating layer 817 so that an impurity such asmoisture entering from the outside of the light-emitting device does noteasily reach the light-emitting element 830.

The driver circuit portion 806 includes a plurality of transistors overthe first flexible substrate 701 with the first bonding layer 703 andthe first insulating layer 705 provided therebetween. In FIG. 16B, oneof the transistors included in the driver circuit portion 806 isillustrated.

Although FIG. 16B illustrates bottom-gate transistors as an example,there is no limitation on the structure of the transistors included inthe light-emitting device of one embodiment of the present invention.

For example, a transistor 848 illustrated in FIGS. 17B to 17D can beused in the light-emitting device of one embodiment of the presentinvention.

FIG. 17B is a top view of the transistor 848. FIG. 17C is across-sectional view in the channel length direction of the transistor848 in the light-emitting device of one embodiment of the presentinvention. The cross section of the transistor 848 illustrated in FIG.17C is taken along the dashed-dotted line X1-X2 in FIG. 17B. FIG. 17D isa cross-sectional view in the channel width direction of the transistor848 in the light-emitting device of one embodiment of the presentinvention. The cross section of the transistor 848 illustrated in FIG.17D is taken along the dashed-dotted line Y1-Y2 in FIG. 17B.

The transistor 848 is a type of top-gate transistor including a backgate.

In the transistor 848, a semiconductor layer 742 is formed over aprojection of an insulating layer 772. When the semiconductor layer 742is provided over the projection of the insulating layer 772, the sidesurface of the semiconductor layer 742 can also be covered with a gate743. Thus, the transistor 848 has a structure in which the semiconductorlayer 742 can be electrically surrounded by an electric field of thegate 743. Such a structure of a transistor in which a semiconductorlayer in which a channel is formed is electrically surrounded by anelectric field of a conductive layer is called a surrounded channel(s-channel) structure. A transistor with an s-channel structure isreferred to as an s-channel transistor.

In the s-channel structure, a channel can be formed in the whole (bulk)of the semiconductor layer 742. In the s-channel structure, the draincurrent of the transistor can be increased, so that a larger amount ofon-state current can be obtained. Furthermore, the entire channelformation region of the semiconductor layer 742 can be depleted by theelectric field of the gate 743. Accordingly, the off-state current ofthe transistor with the s-channel structure can further be reduced.

A back gate 723 is provided over an insulating layer 378.

A conductive layer 744 a provided over an insulating layer 729 iselectrically connected to the semiconductor layer 742 through an opening747 c formed in a gate insulating layer 312, an insulating layer 728,and the insulating layer 729. A conductive layer 744 b provided over theinsulating layer 729 is electrically connected to the semiconductorlayer 742 through an opening 747 d formed in the gate insulating layer312 and the insulating layers 728 and 729.

The gate 743 provided over the gate insulating layer 312 is electricallyconnected to the back gate 723 through an opening 747 a and an opening747 b formed in the gate insulating layer 312 and the insulating layer772. Accordingly, the same potential is supplied to the gate 743 and theback gate 723. Furthermore, either or both of the openings 747 a and 747b may be omitted. In the case where both the openings 747 a and 747 bare omitted, different potentials can be supplied to the back gate 723and the gate 743.

As a semiconductor in the transistor having the s-channel structure, anoxide semiconductor, silicon such as polycrystalline silicon or singlecrystal silicon that is transferred from a single crystal siliconsubstrate, or the like is used.

The first insulating layer 705 and the first flexible substrate 701 areattached to each other with the first bonding layer 703. The secondinsulating layer 715 and the second flexible substrate 711 are attachedto each other with the second bonding layer 713. One or both of thefirst insulating layer 705 and the second insulating layer 715 ispreferably highly resistant to moisture, in which case impurities suchas water can be prevented from entering the light-emitting element 830or the like, leading to higher reliability of the light-emitting device.

The conductive layer 857 is an example of an external connectionelectrode. The conductive layer 857 is electrically connected to anexternal input terminal through which a signal and a potential from theoutside is transmitted to the driver circuit portion 806. Here, anexample in which the FPC 808 is provided as the external input terminalis described. To prevent an increase in the number of manufacturingsteps, the conductive layer 857 is preferably formed using the samematerial and the same step as those of electrodes and wirings in thelight-emitting portion or the driver circuit portion. Here, an exampleis described in which the conductive layer 857 is formed using the samematerial and the same step as those of the electrodes of the transistor820.

In the light-emitting device in FIG. 16B, the FPC 808 is positioned overthe second flexible substrate 711. A connector 825 is connected to theconductive layer 857 through an opening provided in the second flexiblesubstrate 711, the second bonding layer 713, the second insulating layer715, the third bonding layer 822, the insulating layer 817, and theinsulating layer 815. The connector 825 is also connected to the FPC808. The FPC 808 and the conductive layer 857 are electrically connectedto each other via the connector 825. When the conductive layer 857 andthe second flexible substrate 711 overlap with each other, an opening isformed in the second flexible substrate 711 (or a substrate with anopening portion is used) so that the conductive layer 857, the connector825, and the FPC 808 can be electrically connected to each other.

In the case of employing the manufacturing method 3-C described inEmbodiment 1, the step S3-12C (the step of applying pressure to thenon-light-emitting portion) is preferably performed after the conductivelayer 857 is exposed by forming the opening in the second flexiblesubstrate 711 and the like. Accordingly, a decrease in yield of the stepof exposing the conductive layer 857 due to a change in shape of thelight-emitting device can be suppressed.

A modification example of the light-emitting device illustrated in FIGS.16A and 16B is illustrated in FIGS. 18A, 18B, and 19A. FIG. 18A is aplan view of a light-emitting device, and FIG. 18B is an example of across-sectional view taken along the dashed-dotted line D3-D4 in FIG.18A. FIG. 19A is an example of a cross-sectional view taken along thedashed-dotted line D5-D6 in FIG. 18A.

The light-emitting device illustrated in FIGS. 18A and 18B is an examplein which the first flexible substrate 701 and the second flexiblesubstrate 711 have different sizes. The FPC 808 is located over thesecond insulating layer 715 and does not overlap with the secondflexible substrate 711. The connector 825 is connected to the conductivelayer 857 through an opening provided in the second insulating layer715, the third bonding layer 822, the insulating layer 817, and theinsulating layer 815. Since no opening needs to be provided in thesecond flexible substrate 711, there is no limitation on the materialfor the second flexible substrate 711.

In the case of employing the manufacturing method 3-C or 3-D describedin Embodiment 1, the step of applying pressure to the non-light-emittingportion is preferably performed after the conductive layer 857 isexposed by forming the opening in the second insulating layer 715 andthe like. Accordingly, a decrease in yield of the step of exposing theconductive layer 857 due to a change in shape of the light-emittingdevice can be suppressed.

The depression 712 is provided in the non-light-emitting portion of anyof the light-emitting devices illustrated in FIGS. 16B, 17B, 18B, and19A. In the depression 712, the second flexible substrate 711, thesecond bonding layer 713, and the second insulating layer 715 havedepressions. In the depression 712 of the light-emitting deviceillustrated in FIG. 18B and FIG. 19A, the first flexible substrate 701,the first bonding layer 703, and the first insulating layer 705 havedepressions. The non-light-emitting portion has a portion thinner thanthe light-emitting portion in this manner, whereby entry of impuritiesthrough a side surface of the light-emitting device can be inhibited.

In the case where an organic resin with a poor gas barrier property or apoor moisture-resistant property is used for forming the insulatinglayers, it is preferable that the insulating layers not be exposed at anend portion of the light-emitting device. With this structure, entry ofimpurities through a side surface of the light-emitting device can beinhibited. For example, a structure may be employed in which theinsulating layer 817 is not provided at an end portion of thelight-emitting device as illustrated in FIGS. 18B and 19A.

FIG. 19B illustrates a modification example of the light-emittingelement 830.

Note that as illustrated in FIG. 19B, the light-emitting element 830 mayinclude an optical adjustment layer 832 between the lower electrode 831and the EL layer 833. It is preferable to use a conductive materialhaving a light-transmitting property for the optical adjustment layer832. Owing to the combination of a color filter (the coloring layer) anda microcavity structure (the optical adjustment layer), light with highcolor purity can be extracted from the light-emitting device of oneembodiment of the present invention. The thickness of the opticaladjustment layer may be set in accordance with the emission color of thesub-pixel.

Modification examples of the light-emitting device illustrated in FIG.16B are illustrated in FIGS. 20A and 20B and FIGS. 21A and 21B.

Each of the light-emitting devices illustrated in FIGS. 20A and 20B andFIGS. 21A and 21B differs from the light-emitting device illustrated inFIG. 16B in including a spacer 810 in the non-light-emitting portion.

The spacer 810 is preferably positioned at the depression 712. In thatcase, the minimum thickness of the bonding layer 822 can be furtherdecreased.

A surface of the spacer 810 is preferably an insulating film. In thatcase, impurities such as moisture do not easily pass through the spacer810, and the impurities do not easily reach the light-emitting element830. Thus, deterioration of the light-emitting device can be suppressed.

The spacer 810 included in the light-emitting device illustrated in FIG.20A has a structure in which an insulating layer 811 over the insulatinglayer 817 and an inorganic insulating layer 813 over the insulatinglayer 811 are stacked. The insulating layer 811 can be formed using thesame material and the same step as those of the insulating layer 821.The inorganic insulating layer 813 covers a top surface and a sidesurface of the insulating layer 811.

The spacer 810 included in the light-emitting device illustrated in FIG.20B has a structure in which the insulating layer 811 between the secondinsulating layer 715 and the bonding layer 822 and the inorganicinsulating layer 813 between the insulating layer 811 and the bondinglayer 822 are stacked. The inorganic insulating layer 813 covers the topsurface and the side surface of the insulating layer 811.

The spacer 810 may be provided on either the first flexible substrate701 side or the second flexible substrate 711 side or both the firstflexible substrate 701 side and the second flexible substrate 711 side.

The spacer 810 included in the light-emitting device illustrated in FIG.21A has a structure in which the insulating layer 811 over theinsulating layer 817, an insulating layer 812 over the insulating layer811, and the inorganic insulating layer 813 over the insulating layer812 are stacked. The insulating layer 811 can be formed using the samematerial and the same step as those of the insulating layer 821. Theinorganic insulating layer 813 covers a top surface and a side surfaceof the insulating layer 812 and the top surface and the side surface ofthe insulating layer 811.

The spacer 810 included in the light-emitting device illustrated in FIG.21B has a single-layer structure over the insulating layer 817. Thespacer 810 is formed using an inorganic insulating material.

Modification examples of the light-emitting portion 804 and thedepression 712 are illustrated in FIGS. 22A and 22B.

Light-emitting devices illustrated in FIGS. 22A and 22B each includeinsulating layers 817 a and 817 b and a conductive layer 856 over theinsulating layer 817 a. The source electrode or the drain electrode ofthe transistor 820 and the lower electrode of the light-emitting element830 are electrically connected to each other through the conductivelayer 856.

The light-emitting devices in FIGS. 22A and 22B each include a spacer823 over the insulating layer 821 in the light-emitting portion 804. Thespacer 823 can adjust the gap between the first flexible substrate 701and the second flexible substrate 711.

The light-emitting devices in FIGS. 22A and 22B each include an overcoat849 covering the coloring layer 845 and the light-blocking layer 847.The space between the light-emitting element 830 and the overcoat 849 isfilled with the bonding layer 822.

The light-emitting device preferably includes the spacer 810 in thedepression 712. In that case, the minimum thickness of the bonding layer822 can be further decreased.

The spacer 810 included in the light-emitting device illustrated in FIG.22A has a structure in which the insulating layer 811 over theinsulating layer 817 b, the insulating layer 812 over the insulatinglayer 811, and the inorganic insulating layer 813 over the insulatinglayer 812 are stacked. The insulating layer 811 can be formed using thesame material and the same step as those of the insulating layer 821.The insulating layer 812 can be formed using the same material and thesame step as those of the spacer 823 positioned in the light-emittingportion 804. The inorganic insulating layer 813 covers the top surfaceand the side surface of the insulating layer 812 and the top surface andthe side surface of the insulating layer 811.

The light-emitting device illustrated in FIG. 22B differs from thelight-emitting device illustrated in FIG. 22A in that the inorganicinsulating layer 813 covers an end portion of the insulating layer 817 aand an end portion of the insulating layer 817 b. In the case whereorganic insulating layers are used as the insulating layers 817 a and817 b, the end portions thereof are preferably covered with theinorganic insulating layer 813. In that case, entry of impurities suchas moisture into the insulating layer 817 a or 817 b and also arrivalthereof at the light-emitting element 830 can be inhibited.

As illustrated in FIG. 23A, the light-emitting device of one embodimentof the present invention can be a bottom-emission light-emitting deviceusing a color filter method.

The light-emitting device in FIG. 23A includes the first flexiblesubstrate 701, the first bonding layer 703, the first insulating layer705, a first functional layer (a plurality of transistors, theinsulating layer 815, the coloring layer 845, the insulating layer 817a, the insulating layer 817 b, the conductive layer 856, a plurality oflight-emitting elements, and the insulating layer 821), the secondbonding layer 713, and the second flexible substrate 711. The firstflexible substrate 701, the first bonding layer 703, the firstinsulating layer 705, the insulating layer 815, the insulating layer 817a, and the insulating layer 817 b transmit visible light.

The light-emitting portion 804 includes the transistor 820, a transistor824, and the light-emitting element 830 over the first flexiblesubstrate 701 with the first bonding layer 703 and the first insulatinglayer 705 provided therebetween. The light-emitting element 830 includesthe lower electrode 831 over the insulating layer 817 b, the EL layer833 over the lower electrode 831, and the upper electrode 835 over theEL layer 833. The lower electrode 831 is electrically connected to asource electrode or a drain electrode of the transistor 820. An endportion of the lower electrode 831 is covered with the insulating layer821. The upper electrode 835 preferably reflects visible light. Thelower electrode 831 transmits visible light. The coloring layer 845 thatoverlaps with the light-emitting element 830 can be provided anywhere;for example, the coloring layer 845 may be provided between theinsulating layers 817 a and 817 b or between the insulating layers 815and 817 a.

The first insulating layer 705 and the first flexible substrate 701 areattached to each other with the first bonding layer 703. The firstinsulating layer 705 is preferably highly resistant to moisture, inwhich case impurities such as water can be prevented from entering thelight-emitting element 830 and the like, leading to higher reliabilityof the light-emitting device.

The light-emitting device illustrated in FIG. 23A can be manufactured bythe manufacturing method 2 in Embodiment 1. The first insulating layer705 and the first functional layer are formed as the layer to beseparated.

As illustrated in FIG. 23B, the light-emitting device of one embodimentof the present invention can be a top-emission light-emitting deviceusing a separate coloring method.

The light-emitting device in FIG. 23B includes the first flexiblesubstrate 701, the first bonding layer 703, the first insulating layer705, a first functional layer (a plurality of transistors, theinsulating layer 815, the insulating layer 817, a plurality oflight-emitting elements, the insulating layer 821, and the spacer 823),the second bonding layer 713, and the second flexible substrate 711. Thesecond bonding layer 713 and the second flexible substrate 711 transmitvisible light.

The light-emitting device illustrated in FIG. 23B can be manufactured bythe manufacturing method 2 in Embodiment 1. The first insulating layer705 and the first functional layer are formed as the layer to beseparated.

A light-emitting device illustrated in FIG. 23C includes the firstflexible substrate 701, the first bonding layer 703, the firstinsulating layer 705, a first functional layer (a conductive layer 814,a conductive layer 857 a, a conductive layer 857 b, the light-emittingelement 830, and the insulating layer 821), the second bonding layer713, and the second flexible substrate 711.

The light-emitting device illustrated in FIG. 23C can be manufactured bythe manufacturing method 2 in Embodiment 1. The first insulating layer705 and the first functional layer are formed as the layer to beseparated.

The conductive layer 857 a and the conductive layer 857 b, which areexternal connection electrodes of the light-emitting device, can each beelectrically connected to an FPC or the like.

The light-emitting element 830 includes the lower electrode 831, the ELlayer 833, and the upper electrode 835. An end portion of the lowerelectrode 831 is covered with the insulating layer 821. Thelight-emitting element 830 has a bottom emission structure, a topemission structure, or a dual emission structure. The electrode, thesubstrate, the insulating layer, and the like through each of whichlight is extracted transmit visible light. The conductive layer 814 iselectrically connected to the lower electrode 831.

The substrate through which light is extracted may have, as a lightextraction structure, a hemispherical lens, a micro lens array, a filmprovided with an uneven surface structure, a light diffusing film, orthe like. For example, a substrate having the light extraction structurecan be formed by bonding the above lens or film to a resin substratewith an adhesive or the like having substantially the same refractiveindex as the substrate or the lens or film.

The conductive layer 814 is preferably, though not necessarily, providedbecause voltage drop due to the resistance of the lower electrode 831can be inhibited. In addition, for a similar purpose, a conductive layerelectrically connected to the upper electrode 835 may be provided overthe insulating layer 821, the EL layer 833, the upper electrode 835, orthe like.

The conductive layer 814 can be formed to have a single-layer structureor a stacked-layer structure using a material selected from copper,titanium, tantalum, tungsten, molybdenum, chromium, neodymium, scandium,nickel, and aluminum, an alloy material containing any of thesematerials as its main component, or the like. The thickness of theconductive layer 814 can be greater than or equal to 0.1 μm and lessthan or equal to 3 μm, preferably greater than or equal to 0.1 μm andless than or equal to 0.5 μm, for example.

<Examples of Materials>

Next, materials and the like that can be used for the light-emittingdevices are described. Note that description on the components alreadydescribed in this specification is omitted in some cases.

The structure of the transistors in the light-emitting device is notparticularly limited. For example, a planar transistor, a forwardstaggered transistor, or an inverted staggered transistor may be used. Atop-gate transistor or a bottom-gate transistor may be used. Gateelectrodes may be provided above and below a channel.

There is no particular limitation on the crystallinity of asemiconductor material used for the transistors, and an amorphoussemiconductor or a semiconductor having crystallinity (amicrocrystalline semiconductor, a polycrystalline semiconductor, asingle crystal semiconductor, or a semiconductor partly includingcrystal regions) may be used. It is preferable that a semiconductorhaving crystallinity be used, in which case deterioration of thetransistor characteristics can be suppressed.

A semiconductor material used for the semiconductor layer of thetransistor is not particularly limited, and for example, a Group 14element, a compound semiconductor, or an oxide semiconductor can beused. Typically, a semiconductor containing silicon, a semiconductorcontaining gallium arsenide, an oxide semiconductor containing indium,or the like can be used.

An oxide semiconductor is preferably used as a semiconductor where achannel of the transistor is formed. In particular, an oxidesemiconductor having a wider band gap than silicon is preferably used. Asemiconductor material having a wider band gap and a lower carrierdensity than silicon is preferably used because off-state current of thetransistor can be reduced.

For example, the oxide semiconductor preferably contains at least indium(In) or zinc (Zn). Further preferably, the oxide semiconductor containsan oxide represented by an In-M-Zn oxide (M is a metal such as Al, Ti,Ga, Ge, Y, Zr, Sn, La, Ce, Hf, or Nd).

A c-axis aligned crystalline oxide semiconductor (CAAC-OS) is preferablyused as a semiconductor material for the transistors. Unlike amorphoussemiconductor, the CAAC-OS has few defect states, so that thereliability of the transistor can be improved. Moreover, since theCAAC-OS does not have a grain boundary, a stable and uniform film can beformed over a large area, and stress that is caused by bending aflexible light-emitting device does not easily make a crack in a CAAC-OSfilm.

The CAAC-OS is a crystalline oxide semiconductor in which c-axes ofcrystals are oriented in a direction substantially perpendicular to thefilm surface. It has been found that oxide semiconductors have a varietyof crystal structures other than a single-crystal structure. An exampleof such structures is a nano-crystal (nc) structure, which is anaggregate of nanoscale microcrystals. The crystallinity of a CAAC-OSstructure is lower than that of a single-crystal structure and higherthan that of an nc structure.

The CAAC-OS has c-axis alignment, its pellets (nanocrystals) areconnected in an a-b plane direction, and the crystal structure hasdistortion. For this reason, the CAAC-OS can also be referred to as anoxide semiconductor including a c-axis-aligned a-b-plane-anchored (CAA)crystal.

An organic insulating material or an inorganic insulating material canbe used for the insulating layers included in the light-emitting device.Examples of organic resins include an acrylic resin, an epoxy resin, apolyimide resin, a polyamide resin, a polyimide-amide resin, apolysiloxane resin, a benzocyclobutene-based resin, and a phenol resin.Examples of inorganic insulating films include a silicon oxide film, asilicon oxynitride film, a silicon nitride oxide film, a silicon nitridefilm, an aluminum oxide film, a hafnium oxide film, an yttrium oxidefilm, a zirconium oxide film, a gallium oxide film, a tantalum oxidefilm, a magnesium oxide film, a lanthanum oxide film, a cerium oxidefilm, and a neodymium oxide film.

The conductive layers included in the light-emitting device can eachhave, for example, a single-layer structure or a stacked-layer structureincluding any of metals such as aluminum, titanium, chromium, nickel,copper, yttrium, zirconium, molybdenum, silver, tantalum, and tungstenor an alloy containing any of these metals as its main component. Notethat a light-transmitting conductive material such as indium tin oxide,indium oxide containing tungsten oxide, indium zinc oxide containingtungsten oxide, indium oxide containing titanium oxide, indium tin oxidecontaining titanium oxide, indium zinc oxide, or indium tin oxidecontaining silicon oxide may be used for the conductive layers.Alternatively, a semiconductor such as an oxide semiconductor orpolycrystalline silicon whose resistance is lowered by containing animpurity element or the like, or silicide such as nickel silicide may beused.

The light-emitting device of one embodiment of the present invention mayhave any of a top emission structure, a bottom emission structure, and adual emission structure.

When a voltage higher than the threshold voltage of the light-emittingelement is applied between the lower electrode 831 and the upperelectrode 835, holes are injected to the EL layer 833 from the anodeside and electrons are injected to the EL layer 833 from the cathodeside. The injected electrons and holes are recombined in the EL layer833 and a light-emitting substance contained in the EL layer 833 emitslight.

A conductive layer that transmits visible light is used as the electrodethrough which light is extracted. A conductive layer that reflectsvisible light is preferably used as the electrode through which light isnot extracted.

The conductive layer that transmits visible light can be formed using,for example, indium oxide, indium tin oxide (ITO), indium zinc oxide,zinc oxide (ZnO), or zinc oxide to which gallium is added.Alternatively, a film of a metal material such as gold, silver,platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron,cobalt, copper, palladium, or titanium; an alloy containing any of thesemetal materials; or a nitride of any of these metal materials (e.g.,titanium nitride) can be formed thin so as to have a light-transmittingproperty. Alternatively, a stacked film of any of the above materialscan be used as the conductive layer. For example, a stacked film of ITOand an alloy of silver and magnesium is preferably used, in which caseconductivity can be increased. Further alternatively, graphene or thelike may be used.

For the conductive layer that reflects visible light, for example, ametal material such as aluminum, gold, platinum, silver, nickel,tungsten, chromium, molybdenum, iron, cobalt, copper, or palladium or analloy containing any of these metal materials can be used. Further,lanthanum, neodymium, germanium, or the like may be added to the metalmaterial or the alloy. Furthermore, an alloy containing aluminum (analuminum alloy) such as an alloy of aluminum and titanium, an alloy ofaluminum and nickel, an alloy of aluminum and neodymium, or an alloy ofaluminum, nickel, and lanthanum (Al—Ni—La); or an alloy containingsilver such as an alloy of silver and copper, an alloy of silver,palladium, and copper (also referred to as Ag—Pd—Cu or APC), or an alloyof silver and magnesium may be used. An alloy containing silver andcopper is preferable because of its high heat resistance. Further, whena metal film or a metal oxide film is stacked on and in contact with analuminum alloy film, oxidation of the aluminum alloy film can beprevented. Examples of materials for the metal film or the metal oxidefilm include titanium and titanium oxide. Alternatively, the aboveconductive layer that transmits visible light and a film containing ametal material may be stacked. For example, a stacked film of silver andITO or a stacked film of an alloy of silver and magnesium and ITO can beused.

Each of the electrodes can be formed by an evaporation method or asputtering method. Alternatively, a discharging method such as an inkjetmethod, a printing method such as a screen printing method, or a platingmethod may be used.

The EL layer includes at least a light-emitting layer. The EL layer 833may include a plurality of light-emitting layers. In addition to thelight-emitting layer, the EL layer 833 may further include one or morelayers containing any of a substance with a high hole-injectionproperty, a substance with a high hole-transport property, ahole-blocking material, a substance with a high electron-transportproperty, a substance with a high electron-injection property, asubstance with a bipolar property (a substance with a high electron- andhole-transport property), and the like.

For the EL layer 833, either a low molecular compound or a highmolecular compound can be used, and an inorganic compound may also beused. Each of the layers included in the EL layer 833 can be formed byany of the following methods: an evaporation method (including a vacuumevaporation method), a transfer method, a printing method, an inkjetmethod, a coating method, and the like.

The light-emitting element may contain two or more kinds oflight-emitting substances. Thus, for example, a light-emitting elementthat emits white light can be obtained. For example, a white emissioncan be obtained by selecting light-emitting substances so that two ormore kinds of light-emitting substances emit light of complementarycolors. A light-emitting substance that emits red (R) light, green (G)light, blue (B) light, yellow (Y) light, or orange (O) light or alight-emitting substance that emits light containing spectral componentsof two or more of R light, G light, and B light can be used, forexample. A light-emitting substance that emits blue light and alight-emitting substance that emits yellow light may be used, forexample. At this time, the emission spectrum of the light-emittingsubstance that emits yellow light preferably contains spectralcomponents of G light and R light. The emission spectrum of thelight-emitting element preferably has two or more peaks in thewavelength range in a visible region (e.g., greater than or equal to 350nm and less than or equal to 750 nm or greater than or equal to 400 nmand less than or equal to 800 nm).

Moreover, the light-emitting element may be a single element includingone EL layer or a tandem element in which EL layers are stacked with acharge generation layer provided therebetween.

In one embodiment of the present invention, a light-emitting elementcontaining an inorganic compound such as a quantum dot may be employed.Examples of quantum dot materials include a colloidal quantum dotmaterial, an alloyed quantum dot material, a core-shell quantum dotmaterial, a core quantum dot material, and the like. For example, anelement such as cadmium (Cd), selenium (Se), zinc (Zn), sulfur (S),phosphorus (P), indium (In), tellurium (Te), lead (Pb), gallium (Ga),arsenic (As), or aluminum (Al) may be contained.

As the insulating layer 815, an inorganic insulating film such as asilicon oxide film, a silicon oxynitride film, or an aluminum oxide filmcan be used, for example. For example, an organic material such aspolyimide, acrylic, polyamide, polyimide amide, or abenzocyclobutene-based resin can be used for the insulating layer 817,the insulating layer 817 a, and the insulating layer 817 b. It is alsopossible to use a low-dielectric constant material (a low-k material) orthe like. Furthermore, each insulating layer may be formed by stacking aplurality of insulating films.

The insulating layer 821 is formed using an organic insulating materialor an inorganic insulating material. As the resin, for example, apolyimide resin, a polyamide resin, an acrylic resin, a polysiloxaneresin, an epoxy resin, or a phenol resin can be used. It is particularlypreferable that the insulating layer 821 be formed using aphotosensitive resin material to have an opening portion over the lowerelectrode 831 so that a side wall of the insulating layer 821 is formedas an inclined surface with a curvature.

There is no particular limitation on the method for forming theinsulating layer 821; a photolithography method, a sputtering method, anevaporation method, a droplet discharging method (e.g., an inkjetmethod), a printing method (e.g., a screen printing method or an off-setprinting method), or the like can be used.

The spacer 823 can be formed using an inorganic insulating material, anorganic insulating material, a metal material, or the like. As theinorganic insulating material and the organic insulating material, forexample, a variety of materials that can be used for the aforementionedinsulating layers can be used. As the metal material, titanium,aluminum, or the like can be used. When the spacer 823 containing aconductive material is electrically connected to the upper electrode835, a potential drop due to the resistance of the upper electrode 835can be inhibited. The spacer 823 may have either a tapered shape or aninverse tapered shape.

The coloring layer is a coloring layer that transmits light in aspecific wavelength range. For example, a color filter for transmittinglight in a red, green, blue, or yellow wavelength range can be used.Examples of materials that can be used for the coloring layer include ametal material, a resin material, and a resin material containing apigment or dye.

Note that one embodiment of the present invention is not limited to acolor filter method, and a separate coloring method, a color conversionmethod, a quantum dot method, and the like may be employed.

The light-blocking layer is provided between the adjacent coloringlayers. The light-blocking layer blocks light emitted from an adjacentlight-emitting element to inhibit color mixture between adjacentlight-emitting elements. Here, the coloring layer is provided such thatits end portion overlaps with the light-blocking layer, whereby lightleakage can be reduced. As the light-blocking layer, a material that canblock light from the light-emitting element can be used; for example, ablack matrix can be formed using a metal material or a resin materialcontaining pigment or dye. Note that it is preferable to provide thelight-blocking layer in a region other than the light-emitting portion,such as a driver circuit portion, in which case undesired leakage ofguided light or the like can be inhibited.

The overcoat can prevent impurities and the like contained in thecoloring layer from being diffused into the light-emitting element. Theovercoat is formed with a material that transmits light emitted from thelight-emitting element; for example, an inorganic insulating film suchas a silicon nitride film or a silicon oxide film, or an organicinsulating film such as an acrylic film or a polyimide film can be used,and further, a stacked structure of an organic insulating film and aninorganic insulating film may be employed.

In the case where a material of the bonding layer is applied to thecoloring layer and the light-blocking layer, a material with highwettability with respect to the material of the bonding layer ispreferably used as a material of the overcoat. For example, an oxideconductive layer such as an ITO film or a metal film such as an Ag filmwhich is thin enough to transmit light is preferably used as theovercoat.

When the overcoat is formed using a material that has high wettabilitywith respect to the material for the bonding layer, the material for thebonding layer can be uniformly applied. Thus, entry of bubbles in thestep of attaching the pair of substrates to each other can be prevented,and thus defective display can be inhibited.

As the connector, any of various anisotropic conductive films (ACF),anisotropic conductive pastes (ACP), and the like can be used.

Note that the light-emitting device of one embodiment of the presentinvention may be used as a display device or as a lighting device. Forexample, it may be used as a light source such as a backlight or a frontlight, that is, a lighting device for a display panel.

As described above in this embodiment, in the light-emitting device ofone embodiment of the present invention, entry of impurities through aside surface of the light-emitting device can be inhibited because thenon-light-emitting portion has a region thinner than the light-emittingportion. Thus, the light-emitting device can be highly reliable.

This embodiment can be combined with any other embodiment asappropriate.

Embodiment 3

In this embodiment, an input/output device of one embodiment of thepresent invention will be described with reference to drawings. Notethat the above description can be referred to for the components of theinput/output device, which are similar to those of the light-emittingdevice described in Embodiment 2. Although an input/output deviceincluding a light-emitting element is described as an example in thisembodiment, one embodiment of the present invention is not limitedthereto. The input/output device described in this embodiment is also atouch panel.

The input/output devices described in this embodiment each have a regionthinner than a display portion in a non-display portion and are thushighly reliable. Portions other than the display portion (light-emittingportion) in the input/output device can be regarded as the non-displayportions (non-light-emitting portions). In other words, the non-displayportion is provided in a frame-like shape outside a display portion 301or a display portion 501. For example, a driver circuit is part of anon-light-emitting portion.

STRUCTURE EXAMPLE 1

FIG. 24A is a top view of the input/output device. FIG. 24B is across-sectional view taken along the dashed-dotted line A-B anddashed-dotted line C-D in FIG. 24A. FIG. 24C is a cross-sectional viewtaken along the dashed-dotted line E-F in FIG. 24A.

An input/output device 390 illustrated in FIG. 24A includes the displayportion 301 (serving also as an input portion), a scan line drivercircuit 303 g(1), an imaging pixel driver circuit 303 g(2), an imagesignal line driver circuit 303 s(1), and an imaging signal line drivercircuit 303 s(2).

The display portion 301 includes a plurality of pixels 302 and aplurality of imaging pixels 308.

The pixel 302 includes a plurality of sub-pixels. Each sub-pixelincludes a light-emitting element and a pixel circuit.

The pixel circuits can supply electric power for driving thelight-emitting element. The pixel circuits are electrically connected towirings through which selection signals are supplied. The pixel circuitsare also electrically connected to wirings through which image signalsare supplied.

The scan line driver circuit 303 g(1) can supply selection signals tothe pixels 302.

The image signal line driver circuit 303 s(1) can supply image signalsto the pixels 302.

A touch sensor can be formed using the imaging pixels 308. Specifically,the imaging pixels 308 can sense a touch of a finger or the like on thedisplay portion 301.

The imaging pixels 308 include photoelectric conversion elements andimaging pixel circuits.

The imaging pixel circuits can drive photoelectric conversion elements.The imaging pixel circuits are electrically connected to wirings throughwhich control signals are supplied. The imaging pixel circuits are alsoelectrically connected to wirings through which power supply potentialsare supplied.

Examples of the control signals include a signal for selecting animaging pixel circuit from which a recorded imaging signal is read, asignal for initializing an imaging pixel circuit, and a signal fordetermining the time for an imaging pixel circuit to sense light.

The imaging pixel driver circuit 303 g(2) can supply control signals tothe imaging pixels 308.

The imaging signal line driver circuit 303 s(2) can read out imagingsignals.

As illustrated in FIGS. 24B and 24C, the input/output device 390includes the first flexible substrate 701, the first bonding layer 703,the first insulating layer 705, the second flexible substrate 711, thesecond bonding layer 713, and the second insulating layer 715. The firstand second flexible substrates 701 and 711 are attached to each otherwith a third bonding layer 360.

In Structure example 1, a depression is formed in the non-displayportion. In the depression, the thickness of the third bonding layer 360is small. With this structure, entry of impurities into the insidethrough a side surface of the input/output device can be inhibited.

The first flexible substrate 701 and the first insulating layer 705 areattached to each other with the first bonding layer 703. The secondflexible substrate 711 and the second insulating layer 715 are attachedto each other with the second bonding layer 713. Embodiment 2 can bereferred to for materials used for the substrates, the bonding layers,and the insulating layers.

Each of the pixels 302 includes a sub-pixel 302R, a sub-pixel 302G, anda sub-pixel 302B (see FIG. 24C).

For example, the sub-pixel 302R includes a light-emitting element 350Rand the pixel circuit. The pixel circuit includes a transistor 302 tthat can supply electric power to the light-emitting element 350R. Thesub-pixel 302R further includes an optical element (e.g., a coloringlayer 367R that transmits red light).

The light-emitting element 350R includes a lower electrode 351R, an ELlayer 353, and an upper electrode 352, which are stacked in this order(see FIG. 24C).

The EL layer 353 includes a first EL layer 353 a, an intermediate layer354, and a second EL layer 353 b, which are stacked in this order.

Note that a microcavity structure can be provided for the light-emittingelement 350R so that light with a specific wavelength can be efficientlyextracted. Specifically, an EL layer may be provided between a film thatreflects visible light and a film that partly reflects and partlytransmits visible light, which are provided so that light with aspecific wavelength can be efficiently extracted.

The sub-pixel 302R includes the third bonding layer 360 that is incontact with the light-emitting element 350R and the coloring layer367R. The coloring layer 367R is positioned in a region overlapping withthe light-emitting element 350R. Accordingly, part of light emitted fromthe light-emitting element 350R passes through the third bonding layer360 and through the coloring layer 367R and is emitted to the outside ofthe sub-pixel 302R as indicated by an arrow in FIG. 24B or 24C.

The input/output device 390 includes a light-blocking layer 367BM. Thelight-blocking layer 367BM is provided so as to surround the coloringlayer (e.g., the coloring layer 367R).

The input/output device 390 includes an anti-reflective layer 367 ppositioned in a region overlapping with the display portion 301. As theanti-reflective layer 367 p, a circularly polarizing plate can be used,for example.

The input/output device 390 includes an insulating layer 321. Theinsulating layer 321 covers the transistor 302 t and the like. Note thatthe insulating layer 321 can be used as a layer covering unevennesscaused by the pixel circuits and the imaging pixel circuits to provide aflat surface. The transistor 302 t and the like are preferably coveredwith an insulating layer that can inhibit diffusion of impurities to thetransistor 302 t and the like.

The input/output device 390 includes a partition 328 that overlaps withan end portion of the lower electrode 351R. A spacer 329 that controlsthe gap between the first flexible substrate 701 and the second flexiblesubstrate 711 is provided over the partition 328.

The image signal line driver circuit 303 s(1) includes a transistor 303t and a capacitor 303 c. Note that the driver circuit can be formed inthe same process and over the same substrate as those of the pixelcircuits. As illustrated in FIG. 24B, the transistor 303 t may include asecond gate 304 over the insulating layer 321. The second gate 304 maybe electrically connected to a gate of the transistor 303 t, ordifferent potentials may be supplied to these gates. Alternatively, ifnecessary, the second gate 304 may be provided for a transistor 308 t,the transistor 302 t, or the like.

The imaging pixels 308 each include a photoelectric conversion element308 p and an imaging pixel circuit. The imaging pixel circuit can senselight received by the photoelectric conversion element 308 p. Theimaging pixel circuit includes the transistor 308 t. For example, a PINphotodiode can be used as the photoelectric conversion element 308 p.

The input/output device 390 includes a wiring 311 through which a signalis supplied. The wiring 311 is provided with a terminal 319. An FPC 309through which a signal such as an image signal or a synchronizationsignal is supplied is electrically connected to the terminal 319. Aprinted wiring board (PWB) may be attached to the FPC 309.

Note that transistors such as the transistors 302 t, 303 t, and 308 tcan be formed in the same process. Alternatively, the transistors may beformed in different processes.

STRUCTURE EXAMPLE 2

FIGS. 25A and 25B are perspective views of an input/output device 505.FIGS. 25A and 25B illustrate only main components for simplicity. FIGS.26A and 26B are each a cross-sectional view taken along thedashed-dotted line X1-X2 in FIG. 25A.

As illustrated in FIGS. 25A and 25B, the input/output device 505includes the display portion 501, the scan line driver circuit 303 g(1),a touch sensor 595, and the like. Furthermore, the input/output device505 includes the first flexible substrate 701, the second flexiblesubstrate 711, and a flexible substrate 590.

The input/output device 505 includes a plurality of pixels and aplurality of wirings 311. The plurality of wirings 311 can supplysignals to the pixels. The plurality of wirings 311 are arranged to aperipheral portion of the first flexible substrate 701, and part of theplurality of wirings 311 forms the terminal 319. The terminal 319 iselectrically connected to an FPC 509(1).

The input/output device 505 includes the touch sensor 595 and aplurality of wirings 598. The plurality of wirings 598 are electricallyconnected to the touch sensor 595. The plurality of wirings 598 arearranged to a peripheral portion of the flexible substrate 590, and partof the plurality of wirings 598 forms a terminal. The terminal iselectrically connected to an FPC 509(2). Note that in FIG. 25B,electrodes, wirings, and the like of the touch sensor 595 provided onthe back side of the flexible substrate 590 (the side facing the firstflexible substrate 701) are indicated by solid lines for clarity.

As the touch sensor 595, for example, a capacitive touch sensor can beused. Examples of the capacitive touch sensor include a surfacecapacitive touch sensor and a projected capacitive touch sensor. Anexample of using a projected capacitive touch sensor is described here.

Examples of the projected capacitive touch sensor include aself-capacitive touch sensor and a mutual capacitive touch sensor. Theuse of a mutual capacitive touch sensor is preferred because multiplepoints can be sensed simultaneously.

Note that a variety of sensors that can sense the closeness or thecontact of a sensing target such as a finger can be used as the touchsensor 595.

The projected capacitive touch sensor 595 includes electrodes 591 andelectrodes 592. The electrodes 591 are electrically connected to any ofthe plurality of wirings 598, and the electrodes 592 are electricallyconnected to any of the other wirings 598.

The electrodes 592 each have a shape of a plurality of quadranglesarranged in one direction with one corner of a quadrangle connected toone corner of another quadrangle as illustrated in FIGS. 25A and 25B.

The electrodes 591 each have a quadrangular shape and are arranged in adirection intersecting with the direction in which the electrodes 592extend. Note that the plurality of electrodes 591 are not necessarilyarranged in the direction orthogonal to one electrode 592 and may bearranged to intersect with one electrode 592 at an angle of less than 90degrees.

A wiring 594 intersects with the electrode 592. The wiring 594electrically connects two electrodes 591 between which one electrode 592is positioned. The intersecting area of the electrode 592 and the wiring594 is preferably as small as possible. Such a structure allows areduction in the area of a region where the electrodes are not provided,reducing unevenness in light transmittance. As a result, unevenness inluminance of light emitted through the touch sensor 595 can be reduced.

Note that the shapes of the electrodes 591 and the electrodes 592 arenot limited to the above-mentioned shapes and can be any of a variety ofshapes.

As illustrated in FIG. 26A, the input/output device 505 includes thefirst flexible substrate 701, the first bonding layer 703, the firstinsulating layer 705, the second flexible substrate 711, the secondbonding layer 713, and the second insulating layer 715. The first andsecond flexible substrates 701 and 711 are attached to each other withthe third bonding layer 360.

A bonding layer 597 attaches the flexible substrate 590 to the secondflexible substrate 711 so that the touch sensor 595 overlaps with thedisplay portion 501. The bonding layer 597 has a light-transmittingproperty.

The electrodes 591 and the electrodes 592 are formed using alight-transmitting conductive material. As a light-transmittingconductive material, a conductive oxide such as indium oxide, indium tinoxide, indium zinc oxide, zinc oxide, or zinc oxide to which gallium isadded can be used. A film including graphene may be used as well. Thefilm including graphene can be formed, for example, by reducing a filmincluding graphene oxide. As a reducing method, heating or the like canbe employed.

As an example of a material for the conductive layers such as theelectrodes 591, the electrodes 592, and the wirings 594, that is,wirings and electrodes forming a touch panel, a transparent conductivelayer including indium oxide, tin oxide, zinc oxide, or the like (e.g.,ITO) can be given. The resistance of materials used for wirings andelectrodes of the touch panel is preferably low. For example, silver,copper, aluminum, a carbon nanotube, graphene, or a metal halide (suchas silver halide) may be used. Alternatively, a metal nanowire includinga plurality of conductors with an extremely small width (for example, adiameter of several nanometers) may be used. Further alternatively, ametal mesh which is a net-like conductor may be used. For example, an Agnanowire, a Cu nanowire, an Al nanowire, an Ag mesh, a Cu mesh, or an Almesh may be used. In the case of using an Ag nanowire for a wiring or anelectrode of the touch panel, a visible light transmittance of 89% ormore and a sheet resistance of 40 Ω/square or more and 100 Ω/square orless can be achieved. Since the above-described metal nanowire, metalmesh, carbon nanotube, graphene, and the like, which are examples of thematerial that can be used as the wirings and electrodes forming thetouch panel, have high visible light transmittances, they may be used aselectrodes of display elements (e.g., a pixel electrode or a commonelectrode).

The electrodes 591 and the electrodes 592 can be formed by depositing alight-transmitting conductive material on the flexible substrate 590 bya sputtering method and then removing an unneeded portion by a varietyof patterning techniques such as photolithography.

The electrodes 591 and the electrodes 592 are covered with an insulatinglayer 593. Openings reaching the electrodes 591 are formed in theinsulating layer 593, and the wiring 594 electrically connects theadjacent electrodes 591. Alight-transmitting conductive material can befavorably used as the wiring 594 because the aperture ratio of theinput/output device can be increased. Moreover, a material with higherconductivity than the conductivities of the electrodes 591 and theelectrodes 592 can be favorably used for the wiring 594 because electricresistance can be reduced.

Note that an insulating layer covering the insulating layer 593 and thewiring 594 may be provided to protect the touch sensor 595.

A connection layer 599 electrically connects the wirings 598 to the FPC509(2).

The display portion 501 includes a plurality of pixels arranged in amatrix. Each pixel has the same structure as Structure example 1; thus,description is omitted.

As illustrated in FIG. 26B, the touch panel may include two substratesof the first flexible substrate 701 and the second flexible substrate711 without including the flexible substrate 590. The second flexiblesubstrate 711 and the second insulating layer 715 are attached to eachother with the second bonding layer 713, and the touch sensor 595 isprovided in contact with the second insulating layer 715. The coloringlayer 367R and the light-blocking layer 367BM are provided in contactwith an insulating layer 589 that covers the touch sensor 595. Theinsulating layer 589 is not necessarily provided, in which case thecoloring layer 367R and the light-blocking layer 367BM are provided incontact with the wiring 594.

STRUCTURE EXAMPLE 3

FIGS. 27A to 27C are cross-sectional views of an input/output device505B. The input/output device 505B described in this embodiment isdifferent from the input/output device 505 in Structure example 2 inthat received image data is displayed on the side where the transistorsare provided and that the touch sensor is provided on the first flexiblesubstrate 701 side of the display portion. Different structures will bedescribed in detail below, and the above description is referred to forthe other similar structures.

The coloring layer 367R is positioned in a region overlapping with thelight-emitting element 350R. The light-emitting element 350R illustratedin FIG. 27A emits light to the side where the transistor 302 t isprovided. Accordingly, part of light emitted from the light-emittingelement 350R passes through the coloring layer 367R and is emitted tothe outside of the input/output device 505B as indicated by an arrow inFIG. 27A.

The input/output device 505B includes the light-blocking layer 367BM onthe light extraction side. The light-blocking layer 367BM is provided soas to surround the coloring layer (e.g., the coloring layer 367R).

The touch sensor 595 is provided not on the second flexible substrate711 side but on the first flexible substrate 701 side (see FIG. 27A).

The bonding layer 597 attaches the flexible substrate 590 to the firstflexible substrate 701 so that the touch sensor 595 overlaps with thedisplay portion. The bonding layer 597 has a light-transmittingproperty.

Note that a structure in the case of using bottom-gate transistors inthe display portion 501 is illustrated in FIGS. 27A and 27B.

For example, a semiconductor layer containing an oxide semiconductor,amorphous silicon, or the like can be used in the transistor 302 t andthe transistor 303 t illustrated in FIG. 27A.

For example, a semiconductor layer containing polycrystalline siliconcan be used in the transistor 302 t and the transistor 303 t illustratedin FIG. 27B.

A structure in the case of using top-gate transistors is illustrated inFIG. 27C.

For example, a semiconductor layer containing polycrystalline silicon, asingle crystal silicon film that is transferred from a single crystalsilicon substrate, or the like can be used in the transistor 302 t andthe transistor 303 t illustrated in FIG. 27C.

This embodiment can be combined with any other embodiment asappropriate.

Embodiment 4 <Composition of CAC-OS>

Described below is the composition of a cloud aligned complementaryoxide semiconductor (CAC-OS) applicable to a transistor disclosed in oneembodiment of the present invention.

In this specification and the like, a metal oxide means an oxide ofmetal in a broad sense. Metal oxides are classified into an oxideinsulator, an oxide conductor (including a transparent oxide conductor),an oxide semiconductor (also simply referred to as an OS), and the like.For example, a metal oxide used in an active layer of a transistor iscalled an oxide semiconductor in some cases. In other words, an OS FETis a transistor including a metal oxide or an oxide semiconductor.

In this specification, a metal oxide in which regions functioning as aconductor and regions functioning as a dielectric are mixed and whichfunctions as a semiconductor as a whole is defined as a CAC-OS or aCAC-metal oxide.

The CAC-OS has, for example, a composition in which elements included inan oxide semiconductor are unevenly distributed. Materials includingunevenly distributed elements each have a size of greater than or equalto 0.5 nm and less than or equal to 10 nm, preferably greater than orequal to 0.5 nm and less than or equal to 3 nm, or a similar size. Notethat in the following description of an oxide semiconductor, a state inwhich one or more elements are unevenly distributed and regionsincluding the element(s) are mixed is referred to as a mosaic pattern ora patch-like pattern. The region has a size of greater than or equal to0.5 nm and less than or equal to 10 nm, preferably greater than or equalto 0.5 nm and less than or equal to 3 nm, or a similar size.

The physical properties of a region including an unevenly distributedelement are determined by the properties of the element. For example, aregion including an unevenly distributed element which relatively tendsto serve as an insulator among elements included in a metal oxide servesas a dielectric region. In contrast, a region including an unevenlydistributed element which relatively tends to serve as a conductor amongelements included in a metal oxide serves as a conductive region. Amaterial in which conductive regions and dielectric regions are mixed toform a mosaic pattern serves as a semiconductor.

That is, a metal oxide in one embodiment of the present invention is akind of matrix composite or metal matrix composite, in which materialshaving different physical properties are mixed.

Note that an oxide semiconductor preferably contains at least indium. Inparticular, indium and zinc are preferably contained. In addition, anelement M (M is one or more of gallium, aluminum, silicon, boron,yttrium, copper, vanadium, beryllium, titanium, iron, nickel, germanium,zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum,tungsten, magnesium, and the like) may be contained.

For example, of the CAC-OS, an In—Ga—Zn oxide with the CAC composition(such an In—Ga—Zn oxide may be particularly referred to as CAC-IGZO) hasa composition in which materials are separated into indium oxide(InO_(XI), where X1 is a real number greater than 0) or indium zincoxide (In_(X2)Zn_(Y2)O_(Z2), where X2, Y2, and Z2 are real numbersgreater than 0), and gallium oxide (GaO_(X3), where X3 is a real numbergreater than 0), gallium zinc oxide (Ga_(X4)Zn_(Y4)O_(Z4), where X4, Y4,and Z4 are real numbers greater than 0), or the like, and a mosaicpattern is formed. Then, InO_(X1) and In_(X2)Zn_(Y2)O_(Z2) forming themosaic pattern are evenly distributed in the film. This composition isalso referred to as a cloud-like composition.

That is, the CAC-OS is a composite oxide semiconductor with acomposition in which a region including GaO_(X3) as a main component anda region including In_(X2)Zn_(Y2)O_(Z2) or InO_(X1) as a main componentare mixed. Note that in this specification, for example, when the atomicratio of In to an element M in a first region is greater than the atomicratio of In to an element M in a second region, the first region hashigher In concentration than the second region.

Note that a compound including In, Ga, Zn, and O is also known as IGZO.Typical examples of IGZO include a crystalline compound represented byInGaO₃(ZnO)_(m1) (m1 is a natural number) and a crystalline compoundrepresented by In_(1+x0))Ga_((1−x0))O₃(ZnO)_(m0)(−1≤x0≤1; m0 is a givennumber).

The above crystalline compounds have a single crystal structure, apolycrystalline structure, or a CAAC structure. Note that the CAACstructure is a crystal structure in which a plurality of IGZOnanocrystals have c-axis alignment and are connected in the a-b planedirection without alignment.

On the other hand, the CAC-OS relates to the material composition of anoxide semiconductor. In a material composition of a CAC-OS including In,Ga, Zn, and O, nanoparticle regions including Ga as a main component areobserved in part of the CAC-OS and nanoparticle regions including In asa main component are observed in part thereof. These nanoparticleregions are randomly dispersed to form a mosaic pattern. Therefore, thecrystal structure is a secondary element for the CAC-OS.

Note that in the CAC-OS, a stacked-layer structure including two or morefilms with different atomic ratios is not included. For example, atwo-layer structure of a film including In as a main component and afilm including Ga as a main component is not included.

A boundary between the region including GaO_(X3) as a main component andthe region including In_(X2)Zn_(Y2)O_(Z2) or InO_(X1) as a maincomponent is not clearly observed in some cases.

In the case where one or more of aluminum, silicon, boron, yttrium,copper, vanadium, beryllium, titanium, iron, nickel, germanium,zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum,tungsten, magnesium, and the like are contained instead of gallium in aCAC-OS, nanoparticle regions including the selected element(s) as a maincomponent(s) are observed in part of the CAC-OS and nanoparticle regionsincluding In as a main component are observed in part thereof, and thesenanoparticle regions are randomly dispersed to form a mosaic pattern inthe CAC-OS.

<Analysis of CAC-OS>

Next, measurement results of an oxide semiconductor over a substrate bya variety of methods are described.

«Structure of Samples and Formation Method Thereof»

Nine samples of one embodiment of the present invention are describedbelow. The samples are formed at different substrate temperatures andwith different ratios of an oxygen gas flow rate in formation of theoxide semiconductor. Note that each sample includes a substrate and anoxide semiconductor over the substrate.

A method for forming the samples is described.

A glass substrate is used as the substrate. Over the glass substrate, a100-nm-thick In—Ga—Zn oxide is formed as an oxide semiconductor with asputtering apparatus. The formation conditions are as follows: thepressure in a chamber is 0.6 Pa, and an oxide target (with an atomicratio of In:Ga:Zn=4:2:4.1) is used as a target. The oxide targetprovided in the sputtering apparatus is supplied with an AC power of2500 W.

As for the conditions in the formation of the oxide of the nine samples,the substrate temperature is set to a temperature that is not increasedby intentional heating (hereinafter such a temperature is also referredto as room temperature or R.T.), to 130° C., and to 170° C. The ratio ofa flow rate of an oxygen gas to a flow rate of a mixed gas of Ar andoxygen (also referred to as an oxygen gas flow rate ratio) is set to10%, 30%, and 100%.

«Analysis by X-Ray Diffraction»

In this section, results of X-ray diffraction (XRD) measurementperformed on the nine samples are described. As an XRD apparatus, D8ADVANCE manufactured by Bruker AXS is used. The conditions are asfollows: scanning is performed by an out-of-plane method at θ/2θ, thescanning range is 15 deg. to 50 deg., the step width is 0.02 deg., andthe scanning speed is 3.0 deg./min.

FIG. 31 shows XRD spectra measured by an out-of-plane method. In FIG.31, the top row shows the measurement results of the samples formed at asubstrate temperature of 170° C.; the middle row shows the measurementresults of the samples formed at a substrate temperature of 130° C.; thebottom row shows the measurement results of the samples formed at asubstrate temperature of R.T. The left column shows the measurementresults of the samples formed with an oxygen gas flow rate ratio of 10%;the middle column shows the measurement results of the samples formedwith an oxygen gas flow rate ratio of 30%; the right column shows themeasurement results of the samples formed with an oxygen gas flow rateratio of 100%.

In the XRD spectra shown in FIG. 31, the higher the substratetemperature at the time of formation is or the higher the oxygen gasflow rate ratio at the time of formation is, the higher the intensity ofthe peak at around 2θ=31° is. Note that it is found that the peak ataround 2θ=31° is derived from a crystalline IGZO compound whose c-axesare aligned in a direction substantially perpendicular to a formationsurface or a top surface of the crystalline IGZO compound (such acompound is also referred to as c-axis aligned crystalline (CAAC) IGZO).

As shown in the XRD spectra in FIG. 31, as the substrate temperature atthe time of formation is lower or the oxygen gas flow rate ratio at thetime of formation is lower, a peak becomes less clear. Accordingly, itis found that there are no alignment in the a-b plane direction andc-axis alignment in the measured areas of the samples that are formed ata lower substrate temperature or with a lower oxygen gas flow rateratio.

«Analysis with Electron Microscope»

This section describes the observation and analysis results of thesamples formed at a substrate temperature of R.T. and with an oxygen gasflow rate ratio of 10% with a high-angle annular dark-field scanningtransmission electron microscope (HAADF-STEM). An image obtained with anHAADF-STEM is also referred to as a TEM image.

Described are the results of image analysis of plan-view images andcross-sectional images obtained with an HAADF-STEM (also referred to asplan-view TEM images and cross-sectional TEM images, respectively). TheTEM images are observed with a spherical aberration corrector function.The HAADF-STEM images are obtained using an atomic resolution analyticalelectron microscope JEM-ARM200F manufactured by JEOL Ltd. under thefollowing conditions: the acceleration voltage is 200 kV, andirradiation with an electron beam with a diameter of approximately 0.1nm is performed.

FIG. 32A is a plan-view TEM image of the sample formed at a substratetemperature of R.T. and with an oxygen gas flow rate ratio of 10%. FIG.32B is a cross-sectional TEM image of the sample formed at a substratetemperature of R.T. and with an oxygen gas flow rate ratio of 10%.

«Analysis of Electron Diffraction Patterns»

This section describes electron diffraction patterns obtained byirradiation of the sample formed at a substrate temperature of R.T. andan oxygen gas flow rate ratio of 10% with an electron beam with a probediameter of 1 nm (also referred to as a nanobeam).

Electron diffraction patterns of points indicated by black dots a1, a2,a3, a4, and a5 in the plan-view TEM image in FIG. 32A of the sampleformed at a substrate temperature of R.T. and an oxygen gas flow rateratio of 10% are observed. Note that the electron diffraction patternsare observed while electron beam irradiation is performed at a constantrate for 35 seconds. FIGS. 32C, 32D, 32E, 32F, and 32G show the resultsof the points indicated by the black dots a1, a2, a3, a4, and a5,respectively.

In FIGS. 32C, 32D, 32E, 32F, and 32G, regions with high luminance in acircular (ring) pattern can be shown. Furthermore, a plurality of spotscan be shown in a ring-like shape.

Electron diffraction patterns of points indicated by black dots b1, b2,b3, b4, and b5 in the cross-sectional TEM image in FIG. 32B of thesample formed at a substrate temperature of R.T. and an oxygen gas flowrate ratio of 10% are observed. FIGS. 32H, 32I, 32J, 32K, and 32L showthe results of the points indicated by the black dots b1, b2, b3, b4,and b5, respectively.

In FIGS. 32H, 32I, 32J, 32K, and 32L, regions with high luminance in aring pattern can be shown. Furthermore, a plurality of spots can beshown in a ring-like shape.

For example, when an electron beam with a probe diameter of 300 nm isincident on a CAAC-OS including an InGaZnO₄ crystal in a directionparallel to the sample surface, a diffraction pattern including a spotderived from the (009) plane of the InGaZnO₄ crystal is obtained. Thatis, the CAAC-OS has c-axis alignment and the c-axes are aligned in thedirection substantially perpendicular to the formation surface or thetop surface of the CAAC-OS. Meanwhile, a ring-like diffraction patternis shown when an electron beam with a probe diameter of 300 nm isincident on the same sample in a direction perpendicular to the samplesurface. That is, it is found that the CAAC-OS has neither a-axisalignment nor b-axis alignment.

Furthermore, a diffraction pattern like a halo pattern is observed whenan oxide semiconductor including a nanocrystal (a nanocrystalline oxidesemiconductor (nc-OS)) is subjected to electron diffraction using anelectron beam with a large probe diameter (e.g., 50 nm or larger).Meanwhile, bright spots are shown in a nanobeam electron diffractionpattern of the nc-OS obtained using an electron beam with a small probediameter (e.g., smaller than 50 nm). Furthermore, in a nanobeam electrondiffraction pattern of the nc-OS, regions with high luminance in acircular (ring) pattern are shown in some cases. Also in a nanobeamelectron diffraction pattern of the nc-OS, a plurality of bright spotsare shown in a ring-like shape in some cases.

The electron diffraction pattern of the sample formed at a substratetemperature of R.T. and with an oxygen gas flow rate ratio of 10% hasregions with high luminance in a ring pattern and a plurality of brightspots appear in the ring-like pattern. Accordingly, the sample formed ata substrate temperature of R.T. and with an oxygen gas flow rate ratioof 10% exhibits an electron diffraction pattern similar to that of thenc-OS and does not show alignment in the plane direction and thecross-sectional direction.

According to what is described above, an oxide semiconductor formed at alow substrate temperature or with a low oxygen gas flow rate ratio islikely to have characteristics distinctly different from those of anoxide semiconductor film having an amorphous structure and an oxidesemiconductor film having a single crystal structure.

«Elementary Analysis»

This section describes the analysis results of elements included in thesample formed at a substrate temperature of R.T. and with an oxygen gasflow rate ratio of 10%. For the analysis, by energy dispersive X-rayspectroscopy (EDX), EDX mapping images are obtained. An energydispersive X-ray spectrometer AnalysisStation JED-2300T manufactured byJEOL Ltd. is used as an elementary analysis apparatus in the EDXmeasurement. A Si drift detector is used to detect an X-ray emitted fromthe sample.

In the EDX measurement, an EDX spectrum of a point is obtained in such amanner that electron beam irradiation is performed on the point in adetection target region of a sample, and the energy of characteristicX-ray of the sample generated by the irradiation and its frequency aremeasured. In this embodiment, peaks of an EDX spectrum of the point areattributed to electron transition to the L shell in an In atom, electrontransition to the K shell in a Ga atom, and electron transition to the Kshell in a Zn atom and the K shell in an O atom, and the proportions ofthe atoms in the point are calculated. An EDX mapping image indicatingdistributions of proportions of atoms can be obtained through theprocess in an analysis target region of a sample.

FIGS. 33A to 33C show EDX mapping images in a cross section of thesample formed at a substrate temperature of R.T. and with an oxygen gasflow rate ratio of 10%. FIG. 33A shows an EDX mapping image of Ga atoms.The proportion of the Ga atoms in all the atoms is 1.18 atomic % to18.64 atomic %. FIG. 33B shows an EDX mapping image of In atoms. Theproportion of the In atoms in all the atoms is 9.28 atomic % to 33.74atomic %. FIG. 33C shows an EDX mapping image of Zn atoms. Theproportion of the Zn atoms in all the atoms is 6.69 atomic % to 24.99atomic %. FIGS. 33A to 33C show the same region in the cross section ofthe sample formed at a substrate temperature of R.T. and with an oxygengas flow rate ratio of 10%. In the EDX mapping images, the proportion ofan element is indicated by grayscale: the more measured atoms exist in aregion, the brighter the region is; the less measured atoms exist in aregion, the darker the region is. The magnification of the EDX mappingimages in FIGS. 33A to 33C is 7200000 times.

The EDX mapping images in FIGS. 33A to 33C show relative distribution ofbrightness indicating that each element has a distribution in the sampleformed at a substrate temperature of R.T. and with an oxygen gas flowrate ratio of 10%. Areas surrounded by solid lines and areas surroundedby dashed lines in FIGS. 33A to 33C are examined.

In FIG. 33A, a relatively dark region occupies a large area in the areasurrounded by the solid line, while a relatively bright region occupiesa large area in the area surrounded by the dashed line. In FIG. 33B, arelatively bright region occupies a large area in the area surrounded bythe solid line, while a relatively dark region occupies a large area inthe area surrounded by the dashed line.

That is, the areas surrounded by the solid lines are regions including arelatively large number of In atoms and the areas surrounded by thedashed lines are regions including a relatively small number of Inatoms. In FIG. 33C, the right portion of the area surrounded by thesolid line is relatively bright and the left portion thereof isrelatively dark. Thus, the area surrounded by the solid line is a regionincluding In_(X2)Zn_(Y2)O_(Z2), InO_(X1), and the like as maincomponents.

The area surrounded by the solid line is a region including a relativelysmall number of Ga atoms and the area surrounded by the dashed line is aregion including a relatively large number of Ga atoms. In FIG. 33C, theupper left portion of the area surrounded by the dashed line isrelatively bright and the lower right portion thereof is relativelydark. Thus, the area surrounded by the dashed line is a region includingGaO_(X3), Ga_(X4)Zn_(Y4)O_(Z4), and the like as main components.

Furthermore, as shown in FIGS. 33A to 33C, the In atoms are relativelymore uniformly distributed than the Ga atoms, and regions includingInO_(X1) as a main component is seemingly joined to each other through aregion including In_(X2)Zn_(Y2)O_(Z2) as a main component. Thus, theregions including In_(X2)Zn_(Y2)O_(Z2) and InO_(X1) as main componentsextend like a cloud.

An In—Ga—Zn oxide having a composition in which the regions includingGaO_(X3) or the like as a main component and the regions includingIn_(X2)Zn_(Y2)O_(Z2) or InO_(X1) as a main component are unevenlydistributed and mixed can be referred to as a CAC-OS.

The crystal structure of the CAC-OS includes an nc structure. In anelectron diffraction pattern of the CAC-OS with the nc structure,several or more bright spots appear in addition to bright sports derivedfrom IGZO including a single crystal, a polycrystal, or a CAAC.Alternatively, the crystal structure is defined as having high luminanceregions appearing in a ring pattern in addition to the several or morebright spots.

As shown in FIGS. 33A to 33C, each of the regions including GaO_(X3) orthe like as a main component and the regions includingIn_(X2)Zn_(Y2)O_(Z2) or InO_(X1) as a main component has a size ofgreater than or equal to 0.5 nm and less than or equal to 10 nm, orgreater than or equal to 1 nm and less than or equal to 3 nm. Note thatit is preferable that a diameter of a region including each metalelement as a main component be greater than or equal to 1 nm and lessthan or equal to 2 nm in the EDX mapping images.

As described above, the CAC-OS has a structure different from that of anIGZO compound in which metal elements are evenly distributed, and hascharacteristics different from those of the IGZO compound. That is, inthe CAC-OS, regions including GaO_(X3) or the like as a main componentand regions including In_(X2)Zn_(Y2)O_(Z2) or InO_(X1) as a maincomponent are separated to form a mosaic pattern.

The conductivity of a region including In_(X2)Zn_(Y2)O_(Z2) or InO_(X1)as a main component is higher than that of a region including GaO_(X3)or the like as a main component. In other words, when carriers flowthrough regions including In_(X2)Zn_(Y2)O_(Z2) or InO_(X1) as a maincomponent, the conductivity of an oxide semiconductor exhibits.Accordingly, when regions including In_(X2)Zn_(Y2)O_(Z2) or InO_(X1) asa main component are distributed in an oxide semiconductor like a cloud,high field-effect mobility (μ) can be achieved.

In contrast, the insulating property of a region including GaO_(X3) orthe like as a main component is higher than that of a region includingIn_(X2)Zn_(Y2)O_(Z2) or InO_(X1) as a main component. In other words,when regions including GaO_(X3) or the like as a main component aredistributed in an oxide semiconductor, leakage current can be suppressedand favorable switching operation can be achieved.

Accordingly, when a CAC-OS is used for a semiconductor element, theinsulating property derived from GaO_(X3) or the like and theconductivity derived from In_(X2)Zn_(Y2)O_(Z2) or InO_(X1) complementeach other, whereby high on-state current (Ion) and high field-effectmobility (μ) can be achieved.

A semiconductor element including a CAC-OS has high reliability. Thus,the CAC-OS is suitably used in a variety of semiconductor devicestypified by a display.

This embodiment can be combined with any other embodiment asappropriate.

Embodiment 5

In this embodiment, electronic devices and lighting devices of oneembodiment of the present invention will be described with reference todrawings.

Highly reliable electronic devices or lighting devices can bemanufactured by using the light-emitting device, display device,input/output device, or the like of one embodiment of the presentinvention. Furthermore, highly reliable electronic devices or lightingdevices that have a curved surface or flexibility can be manufactured byusing the light-emitting device, display device, input/output device, orthe like of one embodiment of the present invention.

Examples of electronic devices are television devices (also referred toas TV or television receivers), monitors for computers and the like,cameras such as digital cameras and digital video cameras, digital photoframes, cellular phones (also referred to as portable telephonedevices), portable game machines, portable information terminals, audioplayback devices, large game machines such as pin-ball machines, and thelike.

The electronic device or the lighting device of one embodiment of thepresent invention has flexibility and thus can be incorporated along acurved inside/outside wall surface of a house or a building or a curvedinterior/exterior surface of a car.

Furthermore, the electronic device of one embodiment of the presentinvention may include a secondary battery. It is preferable that thesecondary battery be capable of being charged by non-contact powertransmission.

Examples of the secondary battery include a lithium ion secondarybattery such as a lithium polymer battery using a gel electrolyte(lithium ion polymer battery), a nickel-hydride battery, anickel-cadmium battery, an organic radical battery, a lead-acid battery,an air secondary battery, a nickel-zinc battery, and a silver-zincbattery.

The electronic device of one embodiment of the present invention mayinclude an antenna. When a signal is received by the antenna, theelectronic device can display an image, data, or the like on a displayportion. When the electronic device includes the antenna and a secondarybattery, the antenna may be used for contactless power transmission.

FIGS. 28A, 28B, 28C1, 28C2, 28D, and 28E illustrate examples ofelectronic devices each including a display portion 7000 with a curvedsurface. The display surface of the display portion 7000 is curved, andimages can be displayed on the curved display surface. Note that thedisplay portion 7000 may be flexible.

The display portion 7000 is manufactured using the light-emittingdevice, display device, input/output device, or the like of oneembodiment of the present invention.

In accordance with one embodiment of the present invention, a highlyreliable electronic device having a curved display portion can beprovided.

FIG. 28A illustrates an example of a cellular phone. A cellular phone7100 is provided with a housing 7101, the display portion 7000,operation buttons 7103, an external connection port 7104, a speaker7105, a microphone 7106, and the like.

The cellular phone 7100 illustrated in FIG. 28A includes a touch sensorin the display portion 7000. Moreover, operations such as making a calland inputting a letter can be performed by touch on the display portion7000 with a finger, a stylus, or the like.

The power can be turned on or off with the operation button 7103. Inaddition, types of images displayed on the display portion 7000 can beswitched; for example, switching images from a mail creation screen to amain menu screen is performed with the operation button 7103.

FIG. 28B illustrates an example of a television set. In a television set7200, the display portion 7000 is incorporated into the housing 7201.Here, the housing 7201 is supported by a stand 7203.

The television set 7200 illustrated in FIG. 28B can be operated with anoperation switch of the housing 7201 or a separate remote controller7211. Alternatively, the display portion 7000 may include a touchsensor. The display portion 7000 can be operated by touching the displayportion with a finger or the like. The remote controller 7211 may beprovided with a display portion for displaying data output from theremote controller 7211. With operation keys or a touch panel of theremote controller 7211, channels and volume can be controlled and imagesdisplayed on the display portion 7000 can be controlled.

Note that the television set 7200 is provided with a receiver, a modem,or the like. A general television broadcast can be received with thereceiver. Furthermore, when the television set is connected to acommunication network with or without wires via the modem, one-way (froma transmitter to a receiver) or two-way (between a transmitter and areceiver or between receivers) data communication can be performed.

FIGS. 28C1, 28C2, 28D, and 28E illustrate examples of portableinformation terminals. Each portable information terminal includes ahousing 7301 and the display portion 7000. Each portable informationterminal may also include an operation button, an external connectionport, a speaker, a microphone, an antenna, a battery, or the like. Thedisplay portion 7000 is provided with a touch sensor. An operation ofthe portable information terminal can be performed by touching thedisplay portion 7000 with a finger, a stylus, or the like.

FIG. 28C1 is a perspective view of a portable information terminal 7300.FIG. 28C2 is a top view of the portable information terminal 7300. FIG.28D is a perspective view of a portable information terminal 7310. FIG.28E is a perspective view of a portable information terminal 7320.

Each of the portable information terminals illustrated in thisembodiment functions as, for example, one or more of a telephone set, anotebook, and an information browsing system. Specifically, each of theportable information terminals can be used as a smartphone. Each of theportable information terminals illustrated in this embodiment is capableof executing a variety of applications such as mobile phone calls,e-mailing, reading and editing texts, music reproduction, Internetcommunication, and a computer game, for example.

The portable information terminals 7300, 7310, and 7320 can each displaycharacters, image information, and the like on its plurality ofsurfaces. For example, as illustrated in FIGS. 28C1 and 28D, threeoperation buttons 7302 can be displayed on one surface, and information7303 indicated by a rectangle can be displayed on another surface. FIGS.28C1 and 28C2 illustrate an example in which information is displayed atthe top of the portable information terminal. FIG. 28D illustrates anexample in which information is displayed on the side of the portableinformation terminal. Information may also be displayed on three or moresurfaces of the portable information terminal. FIG. 28E illustrates anexample where information 7304, information 7305, and information 7306are displayed on different surfaces.

Examples of the information include notification from a socialnetworking service (SNS), display indicating reception of an e-mail oran incoming call, the subject of an e-mail or the like, the sender of ane-mail or the like, the date, the time, remaining battery level, and thereception strength of an antenna. Alternatively, the operation button,an icon, or the like may be displayed in place of the information.

For example, a user of the portable information terminal 7300 can seethe display (here, the information 7303) with the portable informationterminal 7300 put in a breast pocket of his/her clothes.

Specifically, a caller's phone number, name, or the like of an incomingcall is displayed in a position that can be seen from above the portableinformation terminal 7300. Thus, the user can see the display withouttaking out the portable information terminal 7300 from the pocket anddecide whether to answer the call.

FIGS. 28F to 28H each illustrate an example of a lighting device havinga curved light-emitting portion.

The light-emitting portion included in the lighting device illustratedin each of FIGS. 28F to 28H can be manufactured using the light-emittingdevice or the like of one embodiment of the present invention.

In accordance with one embodiment of the present invention, a highlyreliable lighting device having a curved light-emitting portion can beprovided.

A lighting device 7400 illustrated in FIG. 28F includes a light-emittingportion 7402 having a wave-shaped light-emitting surface, which is agood-design lighting device.

A light-emitting portion 7412 included in a lighting device 7410illustrated in FIG. 28G has two convex-curved light-emitting portionssymmetrically placed. Thus, light radiates from the lighting device7410.

A lighting device 7420 illustrated in FIG. 28H includes a concave-curvedlight-emitting portion 7422. This is suitable for illuminating aspecific range because light emitted from the light-emitting portion7422 is collected to the front of the lighting device 7420. In addition,with this structure, a shadow is less likely to be produced.

The light-emitting portion included in each of the lighting devices7400, 7410, and 7420 may be flexible. The light-emitting portion may befixed on a plastic member, a movable frame, or the like so that anemission surface of the light-emitting portion can be bent freelydepending on the intended use.

Lighting devices 7400, 7410, and 7420 each include a stage 7401 providedwith an operation switch 7403 and a light-emitting portion supported bythe stage 7401.

Note that although the lighting device in which the light-emittingportion is supported by the stage is described as an example here, ahousing provided with a light-emitting portion can be fixed on a ceilingor suspended from a ceiling. Since the light-emitting surface can becurved, the light-emitting surface is curved to have a concave shape,whereby a particular area can be brightly illuminated, or thelight-emitting surface is curved to have a convex shape, whereby a wholeroom can be brightly illuminated.

FIGS. 29A1, 29A2, and 29B to 29I each illustrate an example of aportable information terminal including a display portion 7001 havingflexibility.

The display portion 7001 is manufactured using the light-emittingdevice, display device, input/output device, or the like of oneembodiment of the present invention. For example, a light-emittingdevice, a display device, an input/output device, or the like that canbe bent with a radius of curvature of greater than or equal to 0.01 mmand less than or equal to 150 mm can be used. The display portion 7001may include a touch sensor so that the portable information terminal canbe operated by touching the display portion 7001 with a finger or thelike.

In accordance with one embodiment of the present invention, a highlyreliable electronic device having a flexible display portion can beprovided.

FIGS. 29A1 and 29A2 are a perspective view and a side view,respectively, illustrating an example of the portable informationterminal. A portable information terminal 7500 includes a housing 7501,the display portion 7001, a display portion tab 7502, operation buttons7503, and the like.

The portable information terminal 7500 includes a rolled flexibledisplay portion 7001 in the housing 7501. The display portion 7001 canbe pulled out by using the display portion tab 7502.

The portable information terminal 7500 can receive a video signal with acontrol portion incorporated therein and can display the received videoon the display portion 7001. The portable information terminal 7500incorporates a battery. A terminal portion for connecting a connectormay be included in the housing 7501 so that a video signal and power canbe directly supplied from the outside with a wiring.

By pressing the operation buttons 7503, power on/off, switching ofdisplayed videos, and the like can be performed. Although FIGS. 29A1,29A2, and 29B illustrate an example where the operation buttons 7503 arepositioned on a side surface of the portable information terminal 7500,one embodiment of the present invention is not limited thereto. Theoperation buttons 7503 may be placed on a display surface (a frontsurface) or a rear surface of the portable information terminal 7500.

FIG. 29B illustrates the portable information terminal 7500 in a statewhere the display portion 7001 is pulled out. Videos can be displayed onthe display portion 7001 in this state. In addition, the portableinformation terminal 7500 may perform different displays in the statewhere part of the display portion 7001 is rolled as illustrated in FIG.29A1 and in the state where the display portion 7001 is pulled out asillustrated in FIG. 29B. For example, in the state illustrated in FIG.29A1, the rolled portion of the display portion 7001 is put in anon-display state, which results in a reduction in power consumption ofthe portable information terminal 7500.

Note that a reinforcement frame may be provided for a side portion ofthe display portion 7001 so that the display portion 7001 has a flatdisplay surface when pulled out.

Note that in addition to this structure, a speaker may be provided forthe housing so that sound is output with an audio signal receivedtogether with a video signal.

FIGS. 29C to 29E illustrate an example of a foldable portableinformation terminal. FIG. 29C illustrates a portable informationterminal 7600 that is opened. FIG. 29D illustrates the portableinformation terminal 7600 that is being opened or being folded. FIG. 29Eillustrates the portable information terminal 7600 that is folded. Theportable information terminal 7600 is highly portable when folded, andis highly browsable when opened because of a seamless large displayarea.

The display portion 7001 is supported by three housings 7601 joinedtogether by hinges 7602. By folding the portable information terminal7600 at a connection portion between two housings 7601 with the hinges7602, the portable information terminal 7600 can be reversibly changedin shape from an opened state to a folded state.

FIGS. 29F and 29G illustrate an example of a foldable portableinformation terminal. FIG. 29F illustrates a portable informationterminal 7650 that is folded so that the display portion 7001 is on theinside. FIG. 29G illustrates the portable information terminal 7650 thatis folded so that the display portion 7001 is on the outside. Theportable information terminal 7650 includes the display portion 7001 anda non-display portion 7651. When the portable information terminal 7650is not used, the portable information terminal 7650 is folded so thatthe display portion 7001 is on the inside, whereby the display portion7001 can be prevented from being contaminated and damaged.

FIG. 29H illustrates an example of a flexible portable informationterminal. A portable information terminal 7700 includes a housing 7701and the display portion 7001. In addition, the portable informationterminal 7700 may include buttons 7703 a and 7703 b which serve as inputmeans, speakers 7704 a and 7704 b which serve as sound output means, anexternal connection port 7705, a microphone 7706, or the like. Aflexible battery 7709 can be mounted on the portable informationterminal 7700. The battery 7709 may be arranged to overlap with thedisplay portion 7001, for example.

The housing 7701, the display portion 7001, and the battery 7709 areflexible. Thus, it is easy to curve the portable information terminal7700 into a desired shape and to twist the portable information terminal7700. For example, the portable information terminal 7700 can be curvedso that the display portion 7001 is on the inside or on the outside.Alternatively, the portable information terminal 7700 can be used in arolled state. Since the housing 7701 and the display portion 7001 can betransformed freely in this manner, the portable information terminal7700 is less likely to be broken even when the portable informationterminal 7700 falls down or external stress is applied to the portableinformation terminal 7700.

The portable information terminal 7700 can be used effectively invarious situations because the portable information terminal 7700 islightweight. For example, the portable information terminal 7700 can beused in the state where the upper portion of the housing 7701 issuspended by a clip or the like, or in the state where the housing 7701is fixed to a wall by magnets or the like.

FIG. 29I illustrates an example of a wrist-watch-type portableinformation terminal. The portable information terminal 7800 includes aband 7801, the display portion 7001, an input/output terminal 7802,operation buttons 7803, or the like. The band 7801 has a function of ahousing. A flexible battery 7805 can be mounted on the portableinformation terminal 7800. The battery 7805 may overlap with the displayportion 7001 or the band 7801, for example.

The band 7801, the display portion 7001, and the battery 7805 haveflexibility. Thus, the portable information terminal 7800 can be easilycurved to have a desired shape.

With the operation button 7803, a variety of functions such as timesetting, on/off of the power, on/off of wireless communication, settingand cancellation of silent mode, and setting and cancellation of powersaving mode can be performed. For example, the functions of theoperation button 7803 can be set freely by the operating systemincorporated in the portable information terminal 7800.

By touching an icon 7804 displayed on the display portion 7001 with afinger or the like, an application can be started.

The portable information terminal 7800 can employ near fieldcommunication that is a communication method based on an existingcommunication standard. In that case, for example, mutual communicationbetween the portable information terminal 7800 and a headset capable ofwireless communication can be performed, and thus hands-free calling ispossible.

The portable information terminal 7800 may include the input/outputterminal 7802. In the case where the input/output terminal 7802 isincluded, data can be directly transmitted to and received from anotherinformation terminal via a connector. Charging through the input/outputterminal 7802 is also possible. Note that charging of the portableinformation terminal described as an example in this embodiment can beperformed by non-contact power transmission without using theinput/output terminal.

FIG. 30A is an external view of an automobile 9700. FIG. 30B illustratesa driver's seat of the automobile 9700. The automobile 9700 includes acar body 9701, wheels 9702, a windshield 9703, lights 9704, fog lamps9705, and the like. The light-emitting device, display device,input/output device, or the like of one embodiment of the presentinvention can be used in a display portion of the automobile 9700. Forexample, the light-emitting device or the like of one embodiment of thepresent invention can be used in display portions 9710 to 9715illustrated in FIG. 30B. Alternatively, the light-emitting device or thelike of one embodiment of the present invention may be used in thelights 9704 or the fog lamps 9705.

The display portion 9710 and the display portion 9711 are displaydevices provided in the automobile windshield. The light-emitting deviceor the like of one embodiment of the present invention can be asee-through device, through which the opposite side can be seen, byusing a light-transmitting conductive material for its electrodes andwirings. Such a see-through display portion 9710 or 9711 does not hinderdriver's vision during the driving of the automobile 9700. Therefore,the light-emitting device or the like of one embodiment of the presentinvention can be provided in the windshield of the automobile 9700. Notethat in the case where a transistor or the like for driving thelight-emitting device or the like is provided, a transistor havinglight-transmitting properties, such as an organic transistor using anorganic semiconductor material or a transistor using an oxidesemiconductor, is preferably used.

The display portion 9712 is a display device provided on a pillarportion. For example, the display portion 9712 can compensate for theview hindered by the pillar portion by showing an image taken by animaging unit provided on the car body. The display portion 9713 is adisplay device provided on a dashboard portion. For example, the displayportion 9713 can compensate for the view hindered by the dashboardportion by showing an image taken by an imaging unit provided on the carbody. That is, showing an image taken by an imaging unit provided on theoutside of the car body leads to elimination of blind areas andenhancement of safety. In addition, showing an image so as to compensatefor the area which a driver cannot see makes it possible for the driverto confirm safety easily and comfortably.

FIG. 30C illustrates the inside of an automobile in which a bench seatis used as a driver seat and a front passenger seat. A display portion9721 is a display device provided in a door portion. For example, thedisplay portion 9721 can compensate for the view hindered by the doorportion by showing an image taken by an imaging unit provided on the carbody. A display portion 9722 is a display device provided in a steeringwheel. A display portion 9723 is a display device provided in the middleof a seating face of the bench seat. Note that the display device can beused as a seat heater by providing the display device on the seatingface or backrest and by using heat generated by the display device as aheat source.

The display portion 9714, the display portion 9715, or the displayportion 9722 can display a variety of kinds of information such asnavigation data, a speedometer, a tachometer, a mileage, a fuel meter, agearshift indicator, and air-condition setting. The content, layout, orthe like of the display on the display portions can be changed freely bya user as appropriate. The information listed above can also bedisplayed on the display portions 9710 to 9713, 9721, and 9723. Thedisplay portions 9710 to 9715 and 9721 to 9723 can also be used aslighting devices. The display portions 9710 to 9715 and 9721 to 9723 canalso be used as heating devices.

The display portion in which the light-emitting device, display device,input/output device, or the like of one embodiment of the presentinvention is used may have a flat surface.

FIG. 30D illustrates a portable game console including a housing 9801, ahousing 9802, a display portion 9803, a display portion 9804, amicrophone 9805, a speaker 9806, an operation key 9807, a stylus 9808,and the like.

The portable game console illustrated in FIG. 30D includes two displayportions 9803 and 9804. Note that the number of display portions of anelectronic device of one embodiment of the present invention is notlimited to two and can be one or three or more as long as at least onedisplay portion includes the light-emitting device, display device,input/output device, or the like of one embodiment of the presentinvention.

FIG. 30E illustrates a laptop personal computer, which includes ahousing 9821, a display portion 9822, a keyboard 9823, a pointing device9824, and the like.

This embodiment can be combined with any other embodiment asappropriate.

EXPLANATION OF REFERENCE

10: light-emitting device, 11: substrate, 12: bonding layer, 13:insulating layer, 15: light-emitting element, 16: bonding layer, 17:bonding layer, 18 a: partition, 18 b: temporary sealing layer, 18 c:partition, 18 d: temporary sealing layer, 19: substrate, 21: member, 21a: member, 21 b: member, 22: projection, 22 a: projection, 22 b:projection, 25: light-emitting portion, 26: non-light-emitting portion,31: formation substrate, 32: separation layer, 51: formation substrate,52: separation layer, 53: insulating layer, 55: coloring layer, 59:spacer, 251: flexible substrate, 258: thin region, 259: flexiblesubstrate, 301: display portion, 302: pixel, 302B: sub-pixel, 302G:sub-pixel, 302R: sub-pixel, 302 t: transistor, 303 c: capacitor, 303g(1): scan line driver circuit, 303 g(2): imaging pixel driver circuit,303 s(1): image signal line driver circuit, 303 s(2): imaging signalline driver circuit, 303 t: transistor, 304: gate, 308: imaging pixel,308 p: photoelectric conversion element, 308 t: transistor, 309: FPC,311: wiring, 312: gate insulating layer, 319: terminal, 321: insulatinglayer, 328: partition, 329: spacer, 350R: light-emitting element, 351R:lower electrode, 352: upper electrode, 353: EL layer, 353 a: EL layer,353 b: EL layer, 354: intermediate layer, 360: bonding layer, 367BM:light-blocking layer, 367 p: anti-reflective layer, 367R: coloringlayer, 378: insulating layer, 390: input/output device, 501: displayportion, 505: input/output device, 505B: input/output device, 509: FPC,589: insulating layer, 590: flexible substrate, 591: electrode, 592:electrode, 593: insulating layer, 594: wiring, 595: touch sensor, 597:bonding layer, 598: wiring, 599: connection layer, 701: first flexiblesubstrate, 703: first bonding layer, 705: first insulating layer, 711:second flexible substrate, 712: depression, 713: second bonding layer,715: second insulating layer, 723: back gate, 728: insulating layer,729: insulating layer, 742: semiconductor layer, 743: gate, 744 a:conductive layer, 744 b: conductive layer, 747 a: opening, 747 b:opening, 747 c: opening, 747 d: opening, 772: insulating layer, 804:light-emitting portion, 806: driver circuit portion, 808: FPC, 810:spacer, 811: insulating layer, 812: insulating layer, 813: inorganicinsulating layer, 814: conductive layer, 815: insulating layer, 817:insulating layer, 817 a: insulating layer, 817 b: insulating layer, 820:transistor, 821: insulating layer, 822: bonding layer, 823: spacer, 824:transistor, 825: connector, 830: light-emitting element, 831: lowerelectrode, 832: optical adjustment layer, 833: EL layer, 835: upperelectrode, 845: coloring layer, 847: light-blocking layer, 848:transistor, 849: overcoat, 856: conductive layer, 857: conductive layer,857 a: conductive layer, 857 b: conductive layer, 2000 a: upper plate,2000 b: lower plate, 2005 a: cushioning material, 2005 b: cushioningmaterial, 2005 c: cushioning material, 2005 d: cushioning material,2100: substrate, 7000: display portion, 7001: display portion, 7100:cellular phone, 7101: housing, 7103: operation button, 7104: externalconnection port, 7105: speaker, 7106: microphone, 7200: television set,7201: housing, 7203: stand, 7211: remote controller, 7300: portableinformation terminal, 7301: housing, 7302: operation button, 7303:housing, 7304: housing, 7305: housing, 7306: housing, 7310: portableinformation terminal, 7320: portable information terminal, 7400:lighting device, 7401: stage, 7402: light-emitting portion, 7403:operation switch, 7410: lighting device, 7412: light-emitting portion,7420: lighting device, 7422: light-emitting portion, 7500: portableinformation terminal, 7501: housing, 7502: display portion tab, 7503:operation button, 7600: portable information terminal, 7601: housing,7602: hinge, 7650: portable information terminal, 7651: non-displayportion, 7700: portable information terminal, 7701: housing, 7703 a:button, 7703 b: button, 7704 a: speaker, 7704 b: speaker, 7705: externalconnection port, 7706: microphone, 7709: battery, 7800: portableinformation terminal, 7801: band, 7802: input/output terminal, 7803:operation button, 7804: icon, 7805: battery, 9700: automobile, 9701: carbody, 9702: wheel, 9703: windshield, 9704: light, 9705: fog lamp, 9710:display portion, 9711: display portion, 9712: display portion, 9713:display portion, 9714: display portion, 9715: display portion, 9721:display portion, 9722: display portion, 9723: display portion, 9801:housing, 9802: housing, 9803: display portion, 9804: display portion,9805: microphone, 9806: speaker, 9807: operation key, 9808: stylus,9821: housing, 9822: display portion, 9823: keyboard, and 9824: pointingdevice.

This application is based on Japanese Patent Application serial no.2015-150777 filed with Japan Patent Office on Jul. 30, 2015 and JapanesePatent Application serial no. 2016-119834 filed with Japan Patent Officeon Jun. 16, 2016, the entire contents of which are hereby incorporatedby reference.

1. A light-emitting device comprising: a light-emitting portion; and anon-light-emitting portion having a frame-like shape outside thelight-emitting portion; a first flexible substrate; a second flexiblesubstrate; a first bonding layer; a second bonding layer; a firstinsulating layer; and a first functional layer, wherein the firstbonding layer is between the first flexible substrate and the firstinsulating layer, wherein the second bonding layer is between the secondflexible substrate and the first insulating layer, wherein the firstfunctional layer is between the second bonding layer and the firstinsulating layer, wherein the first bonding layer and the second bondinglayer overlap with each other with the first insulating layertherebetween, wherein the light-emitting portion comprises alight-emitting element in the first functional layer, wherein thenon-light-emitting portion comprises a spacer and an inorganicinsulating layer in the first functional layer, wherein the inorganicinsulating layer covers a side surface and a top surface of the spacer,and wherein a gap between the first flexible substrate and the secondflexible substrate is smaller in a first portion of thenon-light-emitting portion than in the light-emitting portion.
 2. Thelight-emitting device according to claim 1, wherein the first portioncomprises the inorganic insulating layer.
 3. A module comprising: thelight-emitting device according to claim 1; and a flexible printedcircuit board or an integrated circuit.
 4. An electronic devicecomprising: the module according to claim 3; and at least one of asensor, an antenna, a battery, a housing, a camera, a speaker, amicrophone, and an operation button.
 5. The light-emitting deviceaccording to claim 1, wherein a second portion of the first bondinglayer is dented, and wherein the second portion of the first bondinglayer overlaps with the first portion of the non-light-emitting portion.6. The light-emitting device according to claim 1, wherein the firstportion has a frame-like shape, and wherein the first portion surroundsthe light-emitting portion.
 7. The light-emitting device according toclaim 1, wherein the first portion has a belt-like shape, and whereinthe first portion is located along an edge of the light-emitting device.8. The light-emitting device according to claim 1, wherein the spacerand the first portion of the first insulating layer overlap with eachother.
 9. A light-emitting device comprising: a light-emitting portion;and a non-light-emitting portion; a first flexible substrate; a secondflexible substrate; a first bonding layer; a second bonding layer; afirst insulating layer; and a first functional layer, wherein thenon-light-emitting portion is between the light-emitting portion and anedge of the light-emitting device, wherein the first bonding layer isbetween the first flexible substrate and the first insulating layer,wherein the second bonding layer is between the second flexiblesubstrate and the first insulating layer, wherein the first functionallayer is between the second bonding layer and the first insulatinglayer, wherein the first bonding layer and the second bonding layeroverlap with each other with the first insulating layer therebetween,wherein the light-emitting portion comprises a light-emitting element inthe first functional layer, wherein a first portion of the firstinsulating layer is dented in the non-light-emitting portion.
 10. Thelight-emitting device according to claim 9, wherein thenon-light-emitting portion has a frame-like shape outside thelight-emitting portion.
 11. The light-emitting device according to claim9, wherein the non-light-emitting portion comprises a spacer in thefirst functional layer.
 12. The light-emitting device according to claim11, wherein the non-light-emitting portion further comprises aninorganic insulating layer in the first functional layer, and whereinthe inorganic insulating layer is in contact with a side surface and atop surface of the spacer.
 13. The light-emitting device according toclaim 11, wherein the spacer and the first portion of the firstinsulating layer overlap with each other.
 14. The light-emitting deviceaccording to claim 9, wherein the first portion has a frame-like shape,and wherein the first portion surrounds the light-emitting portion. 15.The light-emitting device according to claim 9, wherein the firstportion has a belt-like shape, and wherein the first portion is locatedalong the edge of the light-emitting device.